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While planning the light restomod of my '68 Cutlass convertible, I would like to get some thoughts from the group on what are smart upgrades and what are some things that are a waste of money. For context, I am planning for the car to be a fun weekend driver capable of driving long distances comfortably.
For example, upgrading the front drum brakes to disc brakes seems like a smart upgrade, while converting the rear drums to disc might be considered a waste of money.
What are some other examples? What about suspension upgrades? Steering upgrades?
4 wheel Disc brakes: If you plan on driving the car somewhat hard, rear disc brakes will be worth your while depending on what you upgrade to. I would put 98-02 Camaro brakes the whole way around (they might be the same the whole way back to 96 but I am not sure). Before I redid my vista I had 98 Camaro brakes on all four corners and it stopped almost as good as the 14 inch / 13 inch Wilwood brakes I have now. There are guys out there that sell conversion brackets for the front which are pretty much a bolt on to front disc brake spindles and you will have 12 inch rotors the whole way around. You may have to look into adding the back brakes to a factory olds rear due to the non C clip axels. I put a chevy 10 bolt posi I had lying around under my wagon when I had the camaro brakes on it and they were a direct bolt on with a 1/8th inch spacer between the axle flange and backing plates. Even the camaro parking brake cables worked with the original intermediate cable.
Big Sway Bars: UMI makes great front and rear sway bars for not a lot of money. Ride tech also makes great sway bars but are a little more expensive. You will notice a huge difference taking the car around a hard corner at speed with upgraded sway bars front and back.
Tubular Control Arms: You may not notice as much of a difference with these, but you will notice a difference by upgrading to poly bushings on you originals which these will already have so still not a bad idea. UMI makes a great set of rear bars reasonably priced and the cheap front sets you see on ebay or at car shows for ~$300.00 a set work great as well (these are what I have on my wagon).
Fast Ratio Steering Box: While I might not recommend the expensive super fast 12:1 ratio box that I have on my wagon, any box that is a faster ratio than stock will give you a noticeable improvement in cornering.
New Multi Speed Delay Wipers: I would not spend the $700 - $1000 that some companies charge for a bolt in kit, but if you can do some fab work, you can modify a motor off of a late model camaro to work for way less than $100. I cut up the factory mount from a 98 camaro and welded it into my firewall. I also cut and modified the vista and camaro motor arms (the part that spins bolted to the back of the motor) to make the motor work with the original vista/ cutlass linkage. You can buy a brand new camaro motor with the mount and rear arm for around $75 or a used unit for way less. I did have to make my own rotary switch using a variety of resistors and a 3 pole 8 throw rotary switch (I could probably explain how to do this if you are interested and have basic soldering skills). Here are some pics of my firewall after installation:
A/C: If your car does not have factory A/C or you don't want to convert it to work with 134a, the newer Vintage Air Gen IV units work great. I have one in my wagon and it keeps that huge interior nice and cool. I would not get one of the earlier units as they are much smaller and will have trouble keeping you comfortable. I have a buddy with a Gen III unit in a 67 nova and it barely keeps the interior cool.
Interior Insulation: There are many types, but you will want to put a high quality insulation everywhere you can (doors, quarters, firewall, and most importantly the floors) to keep the inside of the car cool and reduce noise.
Power Windows: This is always a plus and if you have some fab skills, you can make a set work from another car. The regulators in my vista are modified from a 66 B body and I made my own harness to work with the switches.
I have a lot of other upgrades that I love on my wagon, but the ones I listed are the ones I feel will give you the most bang for your buck. Here are some shots of my car:
Last edited by Loaded68W34; October 16th, 2020 at 04:50 PM.
Wiring Harness: Depending on how far you are taking the car down and what all you are doing, adding a new wiring harness is a great investment. Lately, I have been using the cheap 21 circuit harnesses you find on ebay for around $100 or less and I am very impressed with them. They will upgrade your system to plastic blade style fuses and each wire is printed with what it goes to along the entire length of the wire similar to a Painless set. They are NOT plug and play like a reproduction harness so you will have to terminate the ends of the wires yourself and they do NOT use the original bulkhead connector on the firewall. If you are planning to smooth the firewall or adding a lot of electronics to your build like fuel injection, electric fans, modern A/C, etc. I would highly recommend one of these kits. As long as you take your time and install it correctly, it will improve the cars reliability. https://www.ebay.com/itm/21-Circuit-...Cclp%3A2334524
Last edited by Loaded68W34; October 17th, 2020 at 06:39 AM.
Frame stiffening being a convertible. I think there are kits available.
Quality parts
A straight frame and body are the starting point.
If you plan on long trips modern seats and air conditioning would be nice.
I rather have the original looking seats and suffer with a stiff back. I would also rather cook than have a air conditioner in the engine bay.
Last edited by Bernhard; October 17th, 2020 at 09:36 AM.
Frame stiffening being a convertible. I think there are kits available.
Quality parts
A straight frame and body are the starting point.
If you plan on long trips modern seats and air conditioning would be nice.
I rather have the original looking seats and suffer with a stiff back. I would also rather cook than have a air conditioner in the engine bay.
Thanks, Bernhard! I will definitely upgrade the air conditioning. The factory A/C looks complete, but it does not work.
Thanks, Loaded68W34! That is a great list of potential upgrades, and thanks for the suggestions.
Were there any upgrades you think are really unnecessary?
I am pretty happy with everything I added to my wagon, but I also really like gadgets and electronics. I did not include some of the Dakota Digital electronics I have in the car on my original list because even though I am very happy with all of them they can get pricey. I really like the Dakota Digital retained accessory power set up but it is close to $190.00. This keeps the accessory power on until you open the door like a modern car and also turns the lights on automatically when it gets dark out. I really like the Dakota Digital Vintage Air controller as well. All you need to do is set it to a temperature and it automatically controls the fan speed, blower outlets, and air temp blowing from the outlets, but they run between $350 and $450 depending on the model you get on top of the rest of the vintage air system so not really necessary over the standard vintage air controls. The VHX gauges are also awesome and upgradable. I have additional modules to show my gear position, fuel rail pressure, and air ride tank pressure on the dash. At over $1000.00 for the dash and additional modules/ sensors I might not consider this a "necessary" upgrade even though I really like it. The huge Wilwood disc brakes were probably not a necessary upgrade over the 98 camaro brakes but they look a lot better. One thing I might add to the list depending on your engine is hydro boost. If your engine makes little vacuum, the hydro boost set up will give you all the power braking you will need. I installed a used booster from a newer F250 and it works great. Originally, I tried running a summit electric vacuum pump with a 7 inch dual diaphragm booster to assist my engine vacuum, but still had little to no power assist so I changed over to the hydro boost when I took the car apart to paint it and it works great. What drive train combination are you thinking about running in your car?
I am pretty happy with everything I added to my wagon, but I also really like gadgets and electronics. I did not include some of the Dakota Digital electronics I have in the car on my original list because even though I am very happy with all of them they can get pricey. I really like the Dakota Digital retained accessory power set up but it is close to $190.00. This keeps the accessory power on until you open the door like a modern car and also turns the lights on automatically when it gets dark out. I really like the Dakota Digital Vintage Air controller as well. All you need to do is set it to a temperature and it automatically controls the fan speed, blower outlets, and air temp blowing from the outlets, but they run between $350 and $450 depending on the model you get on top of the rest of the vintage air system so not really necessary over the standard vintage air controls. The VHX gauges are also awesome and upgradable. I have additional modules to show my gear position, fuel rail pressure, and air ride tank pressure on the dash. At over $1000.00 for the dash and additional modules/ sensors I might not consider this a "necessary" upgrade even though I really like it. The huge Wilwood disc brakes were probably not a necessary upgrade over the 98 camaro brakes but they look a lot better. One thing I might add to the list depending on your engine is hydro boost. If your engine makes little vacuum, the hydro boost set up will give you all the power braking you will need. I installed a used booster from a newer F250 and it works great. Originally, I tried running a summit electric vacuum pump with a 7 inch dual diaphragm booster to assist my engine vacuum, but still had little to no power assist so I changed over to the hydro boost when I took the car apart to paint it and it works great. What drive train combination are you thinking about running in your car?
Thank you for all of the additional details and ideas.
Here is what I have planned for the drivetrain: Edelbrock Performer RPM (7111) Holley Sniper and Ignition (or maybe just a 4bbl Holley 750) New cam - Either Erson cam, E540121, 214 duration & 0.478 lift or Crane Cams, PowerMax 804542, 216/218 at 050, 0.272/0.284 lift Roller timing chain Bore .030 over Forged pistons (aiming for 9.5:1 to 10:1 compression) Upgrade the valves to 2.070/1.625
Port / polish the heads
Replace the Jetaway with a 200-4R Upgrade the rear end from an open 2.78 to a 3.23 posi\
Definitely convert to front discs if not 4 wheel discs
Definitely replace all suspension bushings but possibly modernize
For a driver and not worried about originality, overdrive trans, I like a stick myself, a/c, and if you want to handle/stop and corner ultimate would be a full chassis includes big brakes, rack and pinion and full tube or boxed frame. I love the stock look, wheels would be stock looking but 17's, wide and lastly good power, say 500-600 hp or more. I can always dream, I"m in the middle of doing as close to original as I can do 70 Supreme due to the rarity of it but ^ would be a lot more my speed
For a driver and not worried about originality, overdrive trans, I like a stick myself, a/c, and if you want to handle/stop and corner ultimate would be a full chassis includes big brakes, rack and pinion and full tube or boxed frame. I love the stock look, wheels would be stock looking but 17's, wide and lastly good power, say 500-600 hp or more. I can always dream, I"m in the middle of doing as close to original as I can do 70 Supreme due to the rarity of it but ^ would be a lot more my speed
I had never considered a full rolling chassis upgrade, but that is very interesting.
Honestly, I love how these older cars drive, so I don't want to change it that much. I want to ensure that the car is safe, and things like better stopping speed and tighter steering should help with that.
I'm a big proponent of improving the front suspension geometry - taller ball joints to relocate the roll center, the car will drive, ride, and handle better because you won't need as much spring to try to control it. Use delrin bushings, not polyurethane/polygraphite. Poly bushings are garbage in rotating applications if you don't loosen them up and grease the crap out of them - they bind and stick. Spend money on good shocks (Bilstein, Koni, Ridetech) - cheap shocks either float or get harsh. Skip the rear disc brake upgrade - your parking brake cables will need to be custom as well. Get the faster steering box with heavier torsion bar for better road feel as well.
For the rear suspension, don't bind it up with poly bushings and boxed arms. Boxed arms are good if they have articulating joints (UMI rotojoints or similar). Otherwise, just stick with good rubber bushings.
The biggest improvements to my car were suspension, an overdrive transmission, and brakes.
For the suspension, stay away from polyurethane bushings as much as you can. As mentioned in other posts, it causes enough suspension bind to hurt vs helping handling - especially with the converging four link rear suspension.
If you are not going to fix the front suspension geometry issues, then there is no reason to get aftermarket front control arms. Just refurbish the stock arms with Global West DelAlum bushings. They actually work like a bearing but without the rattling and squeaking of most bearing setups. If you do not install either taller spindles or extended length ball joints, you haven’t addressed the front end geometry and camber curve issues.
In the rear, you need to have bearings on at least one side of the upper and lower control arms to eliminate bind. For the rear lowers control arms, you want a bearing on the axle side and a delalum bushing on the frame side. If you can’t find a delalum bushing, poly is ok. For the upper rear control arm, the bearing goes on the frame side with a factory rubber bushing in the axle housing (the rubber articulates better than poly and cuts down on a lot of gear noise). Even better, bearings in all locations.
Increase the front and rear spring rates. Most vendors such as Global West, Detroit Speed, SPC, UMI, etceterra 1” lowering springs would work - just make sure they have a linear spring rate. Pair the springs with a good set of shock such as Bilstein or Koni if you are on a budget. Stay away from KYB - the valving results in a pretty harsh ride.
Bigger front and rear rear sway bars.
A fast ratio steering box, just make sure that it has a higher rate torsion bar than the current box, Something in the 35 - 40 lb range. If you don’t get a box with a higher torsion bar rate, the steering will be twitchy with no road feel.
I recommend four wheel disk brakes. Drum rears are self energizing and it’s very hard to get them set up where they do not lock up too early. Either way, you want to install an adjustable proportioning valve in the rear brake line to properly balance the system. Even a factory disk and drum setup will benefit from an adjustable valve if you want to optimize threshold braking levels. If you do go to a four wheel disc setup, you need to take the time to properly match all system components. If you don’t, the system will likely generate less clamping force and brake torque than a factory setup and have some serious front to rear bias issues.
An overdrive transmission makes longer highway drives a lot more enjoyable. But, if you do go to an overdrive, I would suggest a steeper rear gear than a 3.23. The 200R4 has a .67 overdrive, so you would be lugging the motor at most reasonable highway speeds with the 3.23.
The most important thing is to thoroughly research things before you ever buy parts. Take a systems approach to each project. All the parts you buy need to work together as a system. You are better off having a selection of good parts that work well together than a few great parts that are then compromised by something else in the system. For example, you buy high end shocks with valving specifically designed around your spring rates. But, because you spent so much money on the shocks, you can only afford rear control arms with polyurethane bushings in all locations. In this instance, the bind from the poly will hurt rear suspension performance far more than the properly valved shocks helped.
Last edited by 70Rocket; October 20th, 2020 at 06:17 AM.
...Fast Ratio Steering Box: While I might not recommend the expensive super fast 12:1 ratio box that I have on my wagon, any box that is a faster ratio than stock will give you a noticeable improvement in cornering...
If not already equipped with (I don't remember if these boxes were optional that early) what the factory called "Variable-Ratio" steering gears, one of those will certainly improve handling
I'm a big proponent of improving the front suspension geometry - taller ball joints to relocate the roll center, the car will drive, ride, and handle better because you won't need as much spring to try to control it. Use delrin bushings, not polyurethane/polygraphite. Poly bushings are garbage in rotating applications if you don't loosen them up and grease the crap out of them - they bind and stick. Spend money on good shocks (Bilstein, Koni, Ridetech) - cheap shocks either float or get harsh. Skip the rear disc brake upgrade - your parking brake cables will need to be custom as well. Get the faster steering box with heavier torsion bar for better road feel as well.
For the rear suspension, don't bind it up with poly bushings and boxed arms. Boxed arms are good if they have articulating joints (UMI rotojoints or similar). Otherwise, just stick with good rubber bushings.
The biggest improvements to my car were suspension, an overdrive transmission, and brakes.
For the suspension, stay away from polyurethane bushings as much as you can. As mentioned in other posts, it causes enough suspension bind to hurts vs helping handling - especially with the converging four link rear suspension.
If you are not going to fix the front suspension geometry issues, then there is no reason to get aftermarket front control arms. Just refurbish the stock arms with Global West DelAlum bushings. They actually work like a bearing but without the rattling and squeaking of most bearing setups. If you do not install either taller spindles or extended length ball joints, you haven’t addressed the front end geometry and camber curve issues.
In the rear, you need to have bearings on at least one side of the upper and lower control arms to eliminate bind. For the rear lowers control arms, you want a bearing on the axle side and a delalum bushing on the frame side. If you can’t find a delalum bushing, poly is ok. For the upper rear control arm, the bearing goes on the frame side with a factory rubber bushing in the axle housing (the rubber articulates better than poly and cuts down on a lot of gear noise). Even better, bearings in all locations.
Increase the front and rear spring rates. Most vendors such as Global West, Detroit Speed, SPC, UMI, etceterra 1” lowering springs would work - just make sure they have a linear spring rate. Pair the springs with a good set of shock such as Bilstein or Koni if you are on a budget. Stay away from KYB - the valving results in a pretty harsh ride.
Bigger front and rear rear sway bars.
A fast ratio steering box, just make sure that it has a higher rate torsion bar than the current box, Something in the 35 - 40 lb range. If you don’t, the steering will be twitchy with no road feel.
I recommend four wheel disk brakes. Drum rears are self energizing and it’s very hard to get them set up where they do not lock up too early. Either way, you want to install an adjustable proportioning valve in the rear brake line to properly balance the system. Even a factory disk and drum setup will benefit from an adjustable valve if you want to optimize threshold braking levels. If you do go to a four wheel disc setup, you need to take the time to properly match all system components. If you don’t, the system will likely generate less clamping force and brake torque than a factory setup and have some serious front to rear bias issues.
An overdrive transmission makes longer highway drives a lot more enjoyable. But, if you do go to an overdrive, I would suggest a steeper rear gear than a 3.23. The 200R4 has a .67 overdrive, so you would be lugging the motor at most reasonable highway speeds with the 3.23.
The most important thing is to thoroughly research things before you ever buy parts. Take a systems approach to each project. All the parts you buy need to work together as a system. You are better off having a selection of good parts that work well together than a few great parts that are then compromised by something else in the system. For example, you buy high end shocks with valving specifically designed around your spring rates. But, because you spent so much money on the shocks, you can only afford rear control arms with polyurethane bushings in all locations. In this instance, the bind from the poly will hurt rear suspension performance far more than the properly valved shocks helped.
Thank you for the very sound and thorough advice. This really hits the mark on what is important and what is not absolutely necessary.
I hear you on the 3.23 with the overdrive. My only concern about steeper gears is needing to swap out the housing, too. I suppose I could switch the entire read end to something other than the O type, but given the 2.78 open rear end that is in the car, I was thinking that a 3.23 would be the best alternative. The engine speed calculator I used showed that the engine would be between 1900 and 2000 RPM at 70 MPH with the overdrive and the 225/70R14 tires and around 1500 RPM at 55mph. It also showed about a 100 RPM difference with a 3.42 rear end. Is this a big enough difference to justify a different rear end?
If not already equipped with (I don't remember if these boxes were optional that early) what the factory called "Variable-Ratio" steering gears, one of those will certainly improve handling
I run a 3.42 and .69 overdrive in my car and its fine, but that is with a 455 and a smaller / conservative cam and a lot of low end torque. I turn around 2350 rpm at 80. I would use at least a 3.42 or even a 3.90 with the 350 with the .67 overdrive. If you didn't have an O type rear, I would suggest a 3.73.
I run a 3.42 and .69 overdrive in my car and its fine, but that is with a 455 and a smaller / conservative cam and a lot of low end torque. I turn around 2350 rpm at 80. I would use at least a 3.42 or even a 3.90 with the 350 with the .67 overdrive. If you didn't have an O type rear, I would suggest a 3.73.
Thanks for the additional information. It is definitely something to consider.
If you use a 68 - 72 Chevelle 10 or 12 bolt, it will bolt right in place of your current rear and a used set of later Camaro brakes (already discussed in my earlier post) will bolt on with almost no modification (spacer between backing plate and rear, mounts for e-brake cables and brake hoses). You will have to bolt or weld on a bracket for the Camaro e-brake cables to mount to the rear end, but after that the cables are a direct fit for the old cables as well. The 10 bolt I mounted my Camaro brakes to is still sitting in front of my garage as I built a 12 bolt for the car when I redid it. I could take some pics of the rear with the brakes and cables on if you want. I used the 98 Camaro master cylinder, cutlass booster, and a new disc/disc proportioning valve when I was running them. They were a huge improvement over the original brakes (it was an original front disc brake car). The only change I would make is to change to an adjustable proportioning valve to fine tune the rear brake bias which I installed with the new Wilwood system. What size wheels are you planning on? The 12 inch Camaro brakes need at least a 16" wheel possibly 17" depending on the design. If you are still on the fence about some of the components, I would suggest seeing if there is anyone close to you who is willing to give you a ride in their car with some of these upgrades to see how they truly perform. I would gladly give you a ride, but Dallas to PA is a bit of a trek.
I have a Sniper on my '76 Cutlass. Still considering for my '70 Nova. There are a LOT of things I like about the Sniper and wouldn't want to steer anyone away from an EFI system. But, as with all "upgrades" it comes with its own issues. The typical stiff, jerky throttle response is problematic but, is easy to resolve. For the most part, I have had a great experience with mine. With that said, IMPO, in addition to being pricey, make sure you have a a very experienced shop set up / program the system. It will be $$$$ well spent. There are a lot of speed shops in DFW that can accommodate this, I have had great success with Rowlett Service Center...right here in Rowlett, TX. Ron (owner) has built up quite a reputation for working on these old cars and Richard has the programing tools / skills to fine tune these Snipers. The biggest issue they have is to damned much business . In addition to his regular car repair business he usually has a quite a few classics in the shop. In any case, they are very good and very fair with their pricing. Just can't be in a big hurry.
I have a Sniper on my '76 Cutlass. Still considering for my '70 Nova. There are a LOT of things I like about the Sniper and wouldn't want to steer anyone away from an EFI system. But, as with all "upgrades" it comes with its own issues. The typical stiff, jerky throttle response is problematic but, is easy to resolve. For the most part, I have had a great experience with mine. With that said, IMPO, in addition to being pricey, make sure you have a a very experienced shop set up / program the system. It will be $$$$ well spent. There are a lot of speed shops in DFW that can accommodate this, I have had great success with Rowlett Service Center...right here in Rowlett, TX. Ron (owner) has built up quite a reputation for working on these old cars and Richard has the programing tools / skills to fine tune these Snipers. The biggest issue they have is to damned much business . In addition to his regular car repair business he usually has a quite a few classics in the shop. In any case, they are very good and very fair with their pricing. Just can't be in a big hurry.
If you use a 68 - 72 Chevelle 10 or 12 bolt, it will bolt right in place of your current rear and a used set of later Camaro brakes (already discussed in my earlier post) will bolt on with almost no modification (spacer between backing plate and rear, mounts for e-brake cables and brake hoses). You will have to bolt or weld on a bracket for the Camaro e-brake cables to mount to the rear end, but after that the cables are a direct fit for the old cables as well. The 10 bolt I mounted my Camaro brakes to is still sitting in front of my garage as I built a 12 bolt for the car when I redid it. I could take some pics of the rear with the brakes and cables on if you want. I used the 98 Camaro master cylinder, cutlass booster, and a new disc/disc proportioning valve when I was running them. They were a huge improvement over the original brakes (it was an original front disc brake car). The only change I would make is to change to an adjustable proportioning valve to fine tune the rear brake bias which I installed with the new Wilwood system. What size wheels are you planning on? The 12 inch Camaro brakes need at least a 16" wheel possibly 17" depending on the design. If you are still on the fence about some of the components, I would suggest seeing if there is anyone close to you who is willing to give you a ride in their car with some of these upgrades to see how they truly perform. I would gladly give you a ride, but Dallas to PA is a bit of a trek.
Be cautious of where your parts come from, saving money doesnt work out so well if the parts turn out to be crap. Always check reviews before buying.
If you are replacing wiring, make sure the wire gage is correct for the load to be carried. Also find out what material is used for the wire insulation. Critters like the soy-based insulation, not so much for the oil based type.
Be cautious of where your parts come from, saving money doesnt work out so well if the parts turn out to be crap. Always check reviews before buying.
If you are replacing wiring, make sure the wire gage is correct for the load to be carried. Also find out what material is used for the wire insulation. Critters like the soy-based insulation, not so much for the oil based type.
Be cautious of where your parts come from, saving money doesnt work out so well if the parts turn out to be crap. Always check reviews before buying.
If you are replacing wiring, make sure the wire gage is correct for the load to be carried. Also find out what material is used for the wire insulation. Critters like the soy-based insulation, not so much for the oil based type.
Very True! This is one of the reasons I am so impressed with the cheap harnesses I have been using from eBay. All of the wires are properly sized for the amperage rating of the circuits. I have installed Painless systems, Ron Francis systems, and lately these "A-team" type systems and I would have to say the eBay systems are very close to the quality of the Painless and RF harnesses if not the same quality at a fraction of the price. One recommendation I would make is to run remote relays to power the headlights up on the radiator support. The wires in the eBay harness are plenty heavy enough, but it is still good insurance. I cannot comment on the type of insulation these kits use, but you are correct that rodents do like soy based insulation which is unfortunately what many car manufacturers have used over the years.
...Also find out what material is used for the wire insulation. Critters like the soy-based insulation, not so much for the oil based type.
^^^
THIS. I work at a large airport and the long term lot for pilots and attendants always has tow trucks in motion on account of the critters eating up the wiring under the vehicles that sit for a week or so!
October 16th, 2020, 03:08 PM
