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I recently bought a 1966 Oldsmobile Jetstar 88 with a 330ci 2bbl V8. I’ve been looking at spicing it up and was wondering what kind of power could be expected from the following upgrades: camshaft, Edelbrock intake #2711, converting to a 4bbl 600-650cfm carb, and converting to a true dual exhaust. I would need to upgrade my transmission also and need recommendations for a cheaper but usable transmission. Not racing or anything just cruising.
also I can’t decipher for the life of me how to identify this motor. The more I read the more confused I get.
Anyways here’s some pictures lol
Last edited by BraydenU; May 13, 2024 at 02:21 PM.
Reason: No questions in newbie thread
Welcome to the site. The transmission in your car is a jetaway with a switch pitch torque converter. Before you decide on mods or trans change read up on your current setup, it's not a dog by cruising standards. To be honest, unless you're going to do something with the lower end of the engine, I would just keep it stock and spend money on other things.
Welcome to the site. The transmission in your car is a jetaway with a switch pitch torque converter. Before you decide on mods or trans change read up on your current setup, it's not a dog by cruising standards. To be honest, unless you're going to do something with the lower end of the engine, I would just keep it stock and spend money on other things.
maybe down the road I’ll get into doing some serious engine mods but for now I just want to spice it up and keep it reliable/simple.
Dual exhaust will be difficult in that car. The location of the steering box and linkage in the 1965-70 Olds full size cars conflicts with running a separate exhaust pipe on the driver's side. Olds offered dual exhaust on the big block car, but not on the 330/350 small block cars. The big blocks with dual exhaust used a unique driver's side exhaust manifold that routed the pipe up and over the steering box. No such manifold exists for the small block. People have modified the big block manifold to work with the small block, but it requires machining and is still very tight. Reproductions of the big block manifold are available.
Personally I would use a Quadrajet and not an aftermarket carb. The 330 came from the factory with an optional Qjet. Any three speed trans will be a better choice than the two speed Jetaway, even with the switch pitch converter. This car uses a long tail trans. A long tail TH350 is nearly a bolt-in swap, but those can be difficult to find. The 2.52 first gear in the TH350 will be a huge improvement off the line than the 1.76:1 first in the Jetaway. Long tail TH400s are more common, and provide the same improvement, but that trans will require a new driveshaft and changes to the e-brake cables because the trans crossmember moves rearward. The good news is that the TH400 uses the same electric kickdown as the Jetaway. The TH350 uses a cable kickdown that will require some bracketry fabrication to use on this car.
Your car to do with as you please, but if I may ... I feel that car was made to be a reliable family cruiser, why change that? It will go fast enough and be able to go on the highway as is, I would leave it alone- maybe a set of cool wheels/tires.....
You might be able to have dual exhaust put on the car by running the driver's side exhaust under the engine like it was from the factory. Instead of mating it to the passenger's side manifold, just run 2 exhaust pipes down the passenger's side and block off the front port on the passenger's side exhaust manifold. My father @Oldsguy did this on his 69 Delta 88 before we modified a driver's side exhaust manifold from a Toronado. We later found out about the reproduction big block manifolds Joe mentioned above.
Dual exhaust will be difficult in that car. The location of the steering box and linkage in the 1965-70 Olds full size cars conflicts with running a separate exhaust pipe on the driver's side. Olds offered dual exhaust on the big block car, but not on the 330/350 small block cars. The big blocks with dual exhaust used a unique driver's side exhaust manifold that routed the pipe up and over the steering box. No such manifold exists for the small block. People have modified the big block manifold to work with the small block, but it requires machining and is still very tight. Reproductions of the big block manifold are available.
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Originally Posted by Olds64
Welcome, awesome Oldsmobile.
You might be able to have dual exhaust put on the car by running the driver's side exhaust under the engine like it was from the factory. Instead of mating it to the passenger's side manifold, just run 2 exhaust pipes down the passenger's side and block off the front port on the passenger's side exhaust manifold. My father @Oldsguy did this on his 69 Delta 88 before we modified a driver's side exhaust manifold from a Toronado. We later found out about the reproduction big block manifolds Joe mentioned above.
What kind of work are we talking for the manifold you sent? I was able to find a reproduction casting for it.
Supertune what you have first to set a baseline before tossing parts at it.
Is the Ignition system up to snuff, all of it, including the three distributor timing events?
Is the fuel delivery system up to snuff, the carb, soft lines, the filter, the pump, and the pick-up in the tank?
Super-tune the ignition and fuel systems first. Then buy one of the two free-flowing mufflers you would choose to install in a dual system.
Install a free-flowing air cleaner element in the stock air cleaner base.
See what all of this yields.
On a newly acquired old car safety should be your first concern. Brake system, soft brake lines, chassis, bushings, et al....then increase Torque output.
Supertune what you have first to set a baseline before tossing parts at it.
Is the Ignition system up to snuff, all of it, including the three distributor timing events?
Is the fuel delivery system up to snuff, the carb, soft lines, the filter, the pump, and the pick-up in the tank?
Super-tune the ignition and fuel systems first. Then buy one of the two free-flowing mufflers you would choose to install in a dual system.
Install a free-flowing air cleaner element in the stock air cleaner base.
See what all of this yields.
On a newly acquired old car safety should be your first concern. Brake system, soft brake lines, chassis, bushings, et al....then increase Torque output.
Maybe not the answer I wanted but the answer I needed. I am looking to rebuild the carb and replace some gaskets. Replaced the radiator with an aluminum Duralast and all the hoses. Next up is oil change after driving another 100 miles or so, that way the Seafoam I added to the crank can work. Valva cover gaskets need replaced. I did replace the intake filter already. The brakes are okay but I need to get them gone through to see what I’m working with. Also did a decent detail of the exterior and interior to tone down the 60 yo car smell lol
My To Do List:
Spark Plugs, Wires, electronic distribution conversion, new coil.
Brake Rebuild
Carb Rebuild
I’m just getting started and it’s got a long way to go before I do anything super fun to it but I am just trying to paint myself a roadmap. Get ideas for projects and parts. I’ve never owned a car so old but I’m already loving it.
im very grateful for you guys and this entire site has a wealth of information!
What kind of work are we talking for the manifold you sent? I was able to find a reproduction casting for it.
As Joe mentioned, the dual exhaust manifold for the big block is reproduced. The manifold Oldsguy and I modified for his 69 Delta 88 was also for the big block. We cut the backside off of the manifold and had it welded back together 180* out. Instead of pointing down, it pointed up.
I suppose you could do the same with a small block exhaust manifold from a later Toronado (77 and newer). It would be easier to run the exhaust down the passenger's side though.
What kind of work are we talking for the manifold you sent? I was able to find a reproduction casting for it.
I believe the flange needed to be milled thinner where it bolts to the block, and possibly some ginding at the outlet, which will be VERY close to the steering box due to the shorter deck height of the 330.
The other thing people have done is retain the original center-dump manifold on the driver's side, run the second exhaust pipe under the oil pan just like the crossover, then run it to the back of the car. You could either use a dual in/dual out muffler in the stock location or run that second pipe back to the driver's side once you clear the back of the trans and into the second muffler.
Welcome aboard,
I’ve got a couple of ‘66 big cars and a few thoughts that might help you.
Unless you upgrade the brakes to at least a dual master cylinder, don’t think of this car as any kind of hot rod. Pretty much every Kia on the road can stop shorter than you, so leave a lot of distance in traffic. Mentally, don’t get p*ssed off if someone cuts in front of you when you’re following distantly. Try to remember you’re enjoying your old car, they’re in traffic.
With a small block Olds and weight of an Olds 88, you’re not going to be setting 0-60 records. Abandon that as a goal, if it ever was. Instead, focus on making your car quiet and reliable. Reliable old cars are fun, especially for family & friends. Use it that way and make an occasion out of a drive. Recreate the experience of a drive as it was in 1966 and focus on what made it fun then.
The best modifications I did to my ‘66 big Olds were good cooling, HEI distributors, 10/12 SI internally regulated alternators and disk brakes. I’d recommend all in the name of safety and reliability.
These are solid cars, especially the big cars - they were usually gently used - but they’re not as safe as today’s cars. Carry a cellphone, fire extinguisher and a few tools to keep the journeys fun.
Wishing you many fun drives with family & friends!
i would highly recommend a rear sway bar ,and a decent exhaust shop can fab duals on that by running the left pipe under the engine and out the right side while running the right side over to the left behind the transmission
