Olds1971

I have posted before. Dropping a 350 olds into my 83 cutlass 3.8. Motor is done and ready to drop in. Whats some last minute things im going to need. I have the 307 motor mounts. Will I need 307 or 350 frame mounts also or will the 3.8 ones work. Also will the torque converter and trans. 350 turbo mount to this motor? I have the v8 shroud. I know to change fuel line sides. Im keeping the battery on stock side just buying longer battery cables. Im not doing dumby lights so will I still need a 350 wire harness?? Anything else im missing before I start?

captjim

I posted this link in your other thread,
http://www.robertpowersmotorsports.com/G-bodyV6-V8.html
everything you need to know is right there.

Intragration

The link from CaptJim is good, I found that after I had started my similar build. You will need Olds mounts, the 350 and 307 mounts should be the same for a G-body. I moved the battery, very easy process and then everything matches up. On G-bodies, the two sides of the inner fenders where the battery and the charcoal canister go are interchangeable, you could just take out the canister and the battery will drop right in on the driver's side. I would recommend doing this.

You'll need to notch the trans crossmember or buy one to allow for duals. Very easy to notch if you have access to a welder. The 3.8 harness can be modified very simply to work with the Olds motor. Some said "don't butcher it, get a 307 harness" but it wasn't a problem. I do good work and I was happy modifying the 3.8 harness. To remove the computer harness I cut it as close to the firewall in the engine compartment as possible, and then just pulled it out from inside the car and plugged up the grommet, very clean and you can use the grommet in the future for other wiring you might need. If the TH350 is a BOP, it will work. If the car had OD, the crossmember may need to be modified for this. If it was a TH200, it will bolt right up. Any more questions, post them and I'll try to help. I have pictures of anything you'd like, although my swap was a BBO.

Olds1971

I have read that link from capt. When you say mounts. Is this motor mounts, frame mounts or both. If you move the battery or canister is it a direct bolt up for each?? I will modify my 3.8 harness so any pictures of that would help. About the trans, whats BOP or OD. When you switched the gas lines from drivers to passenger did you run a line all the way back to the tank or how did you go about that. Also will the torque converter from the v6 bolt to the v8 flywheel?

olds 307 and 403

BOP= Buick, Olds and Pontiac. A chevy trans has a diiferent bell housing pattern. You can get an adaptor plate, I did on my 4x4, Olds 350 to a chevy pattern only 4L60E, newer version of the TH700R4. OD is short for overdrive transmission. The TH2004r all have the BOP bellhousing pattern, some are dual pattern, mine is.

Intragration

You'll need the frame mounts from a 307 G-body. For isolators, the rubber parts, I ordered new ones for a 1970 Olds 98. Some people have said you need to match SBO or BBO frame mounts to isolators, but I haven't found this to be true on a G-body. I've got a a 455 with an Edelbrock Performer intake, an Edelbrock 140x carb and a 2.5" or 3" air cleaner and I have no clearance issues.

When I got my car, there was no canister on the driver's side, but the battery had originally been mounted on the passenger side, it was originally a 3.8. I put the battery on the driver's side and bolted it down, there's already a tray there for it. You may need to move the captive nut clip from the passenger side to the driver's side on the core support. 15 second job.

I don't have any pictures of the harness modification, but it's pretty straightforward. Going from memory, you've got the HEI power wire, and the starter ignition wire, and possibly a wire to the alternator. If any of the wires were way too long, I just cut them down and put on a new connector, and if they were too short, I spliced in proper gauge wire to extend them. Solder and use heat shrink tubing at all joints, not electrical tape. You'll have a wire that goes from the heater blower relay, this has a connector that's probably melted that then extends to the + terminal on the starter, this is for the blower high setting. The only three other wires I can remember are for the oil and temp sensor idiot lights, and one that went to the electric choke with an extension to the oil pressure sensor that interrupts the signal to the choke when the ignition is on but there is no oil pressure. For starter wiring, on my 455 with Hooker 3203 headers, I ran everything down the front corner of the block and straight back to the starter, there's a big opening that keeps it all very far away from the headers, and for additional protection, I covered them all with heat tubing. Your situation may be different.

The correct way to do the fuel line is to run a new one from the tank to the front of the car. I didn't do it this way, I just made a short run from the rubber hose at the front of the crossmember on the driver's side over to the passenger side, with a rubber hose to connect to the fuel pump inlet nipple. See the picture. I drilled a small hole at the front edge of the crossmember and added a clip to secure the fuel line.

The upper radiator hose I used was for a 1976 455 Cutlass. It was a direct fit. The radiator was from a V8 G-body. On the lower radiator hose, it was just for a 307. I hear that newer lower hoses are collapse-proof. I don't buy it, I picked up a spring thing that's supposed to go on the outside of a heater hose to allow you to bend it at an angle, I removed the metal strap that was connected to it, I expanded it to fit snugly inside the lower radiator hose, and I installed it. This prevents the lower hose from collapsing on wide open throttle and staying collapsed on part throttle. See the other picture.

I don't know about the torque converter, I got my motor and trans as a unit.

Olds1971

Isolators? Sorry im new to most this but im learning you explaining this is making it way easier on me and my heart attacks I about had yesterday from hearing all the bs I needed to do. How did you go about getting frame mounts for a 307 and for an 83 whats years of mounts can I use. Keep an eye on this thread at the end of this week im starting this project and will be posting alot of pictures for guildence. But as far as the fuel line ill be doing mine how you did yours for now till I know this acts the way I want it to.

Intragration

Isolators, motor mounts, the things with rubber on them that you bolt to the motor, as opposed to the things you bolt to the frame. You get the isolators from the parts store, they're like $5 each. As I said, I asked for 1970 Olds 98 parts, and they worked perfectly. (Edit: 1970 Olds 98 mounts will NOT work, I got this wrong, see Joe's post #9 below for the correct information) For frame mounts, you can check the classifieds here and on other Oldsmobile or G-body forums or Epay, they're pretty readily available. I believe the 260 was available from '78 to '81 or later, and the 307 was available at some point through the end of production in '88, so any year Olds G-body frame mount will work. Cutlasses and Regals are the most likely candidates, Monte Carlos and Grand Prixs almost never got Olds V8s but there could be exceptions. I did see a GP diesel, this would have been Olds. Plan to spend a good number of hours getting the old frame mounts off and the new ones on. It's not easy to access all the bolts inside the crossmember, but it's entirely possible. You'll need an assortment of u-joints for your wrench and some ingenuity to do it. Here's what the frame mounts look like, and installed. There is a left side and a right side, they're not identical.

I'll be watching closely, and I'm sure it will work out fine.

joe_padavano

NOOOOOO. The 1965-70 Olds full size cars (Eighty Eight and Ninety Eight) use specific motor mounts that have a threaded stud that goes through the frame. No frame brackets are used in those applications and those mounts DO NOT fit other Oldsmobiles.

Once again, the motor mounts and frame mounts need to match each other NOT the block. The 1978-1988 A/G body frame mounts (which are exactly the same as the 1977-1990 B-body frame mounts) for the Olds motors require Anchor Pn? 2328 motor mounts. These happen to be the same mounts as used on the 1969-up BBO A-body cars and the 1971-up full size cars (for ALL motors).

Intragration

I got the mount wrong, Joe is correct. When I bought my mounts, I walked into O'Reilly's and asked for mounts for a '70 Olds 98, and what they gave me were 2328s, which are WRONG for a '70 Olds 98, but are CORRECT for a G-body Olds motor. In other words, I asked for the wrong part, and I accidentally got a different part than I asked for, and it worked for me. O'Reilly's website still lists the wrong part for the '70 application, BTW.

Anyway, 2328 is the part you want for a G-body Olds motor, I stand corrected.

Olds1971

Sweet then I got the right ones. A few weeks ago I bought motor mounts for my 83 only as if it had a 307 in it instead. part number is 2328!!!! WOOT I got one thing right then. Now to find the frame mounts. So frame mounts are stupid hard to get out?

Olds1971

So there is motor mounts that bolt to motor.... I got those... Then frame mounts that go on frame... Im finding those.. What connects the two??

Intragration

Before I did the swap, I thought there was a third part too, based on the descriptions. There are only the two parts though, and a bolt that goes between the two tabs on the motor mount and through the holes in the frame mount. The old frame mounts are a bit of a pain to get out, but it can be done. Some guys have mentioned cutting or drilling them, but I usually save the destructive route for if there's no other way. For some of the bolts I used a box wrench when I had a clear shot, and some I had to use the u-joint 3/8" drive extension. Make sure you have a telescoping magnet before you start, so you can fish your tools out of the crossmember. I think I still have an extension and a socket stuck somewhere in there.

Olds1971

Will I need a V8 radiator or could I use the v6 one? Also can I use a 72 350 fan? I already have a v8 shroud. When I get radiator hoses do I just get the hoses for the motor??

Intragration

I think you're going to need a different radiator, I believe the Olds connections are in different places than the Buick ones on the radiator, and the one you have probably wouldn't have enough cooling capacity anyway. Here's a picture of my radiator if it helps.

The 350 fan SHOULD work, try it out and see. Is it a clutch fan, as opposed to a flex fan? Clutch would have been stock, and is the way to go IMO. Check it to make sure there's some resistance to turning. There are different lengths of water pumps, I don't know all the details, but the stock 455 fan and AC water pump worked on mine. For radiator hoses, yes, you should just be able to use stock Olds V8 G-body hoses with a 350.

How are the gaskets? While the motor is out is a really good time to do the gaskets. I did intake, valve covers and oil pan before I dropped it in. It already had a new water pump. Another thing that's convenient for the future is to mark the balancer with timing marks or a timing tape. This allows you to check total timing without a dial-back timing light. If you already have one of these, you can ignore this. I marked mine up to 45 degrees, with hash marks every 5 degrees. See the other picture.

joe_padavano

A grade 8 bolt.

joe_padavano

The fan, water pump, accessory brackets, and pulleys should be used as a matched set. None of the V6 parts will fit an Olds motor. If you plan to retain the R6 A/C compressor, you'll need the complete accessory drive setup from a 307 motor. Get the bigger radiator. As for the hoses, any you don't replace now, you will be replacing in six months. Or maybe that's just MY luck...

Olds1971

Ok posted a picture of what I have so far. I have the lower alt bracket done But cant remember the life of me how it goes back together, the top ones on the the bottom that the bottom of the alt connects to has the plate then a bar that attach together no idea how to bolt back.. Anyone have a picture of this?????

SBORule

That's because an average amount of these cars came with Diesel's engines, which used two batteries. Finding a G body with a running Diesel in it would be the ultimate car to start with.

coppercutlass

Bruce my dad's 77 pontiac bonneville has the same deal with the 2 tray's . I just thought they adapted the battery tray to accept the canisters as a means to use their resources better. On a side note locally a few of those olds diesels come up on craigslist even the v6's just the engines.

Intragration

Most of them came with gasoline motors though, and in that case, a battery would be installed on the appropriate side. It would seem any car that came with a SBO would be an ideal candidate for an Olds motor swap, I haven't looked into the diesels to know if there were any differences with their electrical or fuel systems that would affect this.

coppercutlass

the mondello books specifies the swap from diesel to gas. If i am correct they sold kit's to convert from diesel to gas with the same short block.

Intragration

The picture is a little small and hard to see, but the motor looks good, Olds1971. I don't know if this is the same bracket setup that you have, but here are a couple of mine. I had started to take it apart, and I realized that it was going to be difficult to remember how it went together so I just quickly snapped these. Hope they help.

Olds1971

YES SIR!!!!!!!!!!!!!!!!!!!!!! THANK YOU lol.. ok now that I know how the alt one goes back should be easier to put on the motor lol. Also ill be posting more pics. I need to know where the wire from the distributor goes. and different vaccum likes and hoses. Also do you have to run a choke thermostat?

Olds1971

Do you have a picture where that alt bracket bolts on at?

Intragration

I don't know a lot about the diesel blocks, but I know they have a lot of potential. They're stronger castings and can be bored out quite a bit. I was just saying I don't think starting with a diesel car is necessarily better than starting with a 307 car, unless you specifically intend to reuse the diesel block.

coppercutlass

Well the diesel as far as i know is great for an all out engine for street strip gas is better. seems like most guys who are dead serious about sbo performance go with the diesel block. The 307 aint a bad little engine. I have one that's on it's last limb here in my 72 and it runs really strong if it had a better cam it would be a strong cruiser. I intend to rebuild the 307 too.

SBORule

That's a really small picture, I can't make out what you have hanging down there on the drivers side of the engine.

On my engine, that lower bracket also supported the power steering pump, there is a bolt that goes on the drivers side top water pump hole that has a stud on the other side of the bolt so you can mount the brackets. There's also the same kind of bolt with a stud on the other end that goes in the top hole on the timing tab.

studbolt_zpsf98844f2.jpg

Intragration posted pictures already, glad I didn't have to go dig out my junk to take pictures for ya.

I removed my power steering bracket and stock alternator bracket and went with a BOP Engineering bracket because I eliminated my power steering pump.

Good to see people get help fast on this site.

Intragration

Is this what you're looking for? This was my motor before I cleaned it up, you can't see anything after it's all in black paint. What kind of carb are you using? I have an Edelbrock, I just ran a manual choke cable to it. Unless you're going to use the car in the winter, you could potentially do without a choke. I ran without for a while, it wasn't a huge deal. There are automatic ones available too, depending on your carb. Are you running points or HEI? On HEI one single connector goes to the ignition power wire from the left harness in the engine bay, one single connector goes to the tach (if equipped) and the dual connector goes to the sensor inside the distributor. If you have points, you're going to have to make some additional changes to the wiring, it requires a resistor or resistor wire, otherwise you'll burn the points out quickly. I don't remember off the top of my head exactly how it would be wired, let us know if you do have points and someone will be able to give you an answer.

Intragration

Ok, I'm running back out to continue scraping the undercarriage from a creeper. I'd MUCH rather stay here and watch your progress Olds1971... I'll check back in later. My suggestion for the moment is, unless you're absolutely certain you've addressed everything, don't rush to get everything hooked up and start the motor prematurely. Take your time, double-check everything and make sure it's right. I have an engine start checklist that I had created before, I'll dig it out later and post it. I go over it a couple times before I start an engine for the first time, just to make sure I didn't miss anything.

SBORule

The dual battery trays were just engineered into the different model's that would have a Diesel engine option, it was just cheeper to do it that way.

Intragration

Some G-bodies got the battery on the left, some got the battery on the right, and some got two batteries. AFAIK there aren't left and right battery-delete inner fenders, they ALL got two trays. And on gasoline cars, they used the tray that wasn't used by a battery for a charcoal canister.

2olds

You will need v8 throttle cable.

Olds1971

I cant figure out how to make the picture bigger on here.... Nothing is hanging off the side its just somthing laying in the back ground. My carb is the OEM two barrel. It will run in the winter. Intragration that pic is exactly what I needed only wrong angle or you could finish it for me. That bar thats attached to the bigger bracet does it bolt to the alt then? I know where everything goes for the powersteering just not the alt. I dont think I have HEI cause the coil is bolted to the motor. right?? Also why would I need a v8 throttle cable (2 olds)? is that one of those jokes like turning signal fluid cause I dont get it lol???

Intragration

I don't think you're going to need the throttle cable. I still have the 3.8 cable in mine. I did have to pick up a throttle bracket, I just used a Spectre. Here's another pic of the alternator, hopefully this helps. Unless there's an aftermarket setup inside your distributor, it sounds like you've got points. The decision you have to make is whether you want to stay with points, or go with HEI or some other electronic ignition. You already have points, and the only downside to them (aside from the fact that you'll need to slightly alter the factory wiring on your car) is that you need to maintain them regularly and you will need a dwell meter to do this. (many people will argue vehemently against points, take this with a grain of salt, I have a points car and it runs great and doesn't require excessive work) If you decide to go with HEI, you'll need to get an HEI distributor, but this would then hook directly up to your factory wiring and not require any ongoing maintenance. Either way, if you don't already have a dwell meter, you're going to need to buy something, either a dwell meter or an HEI distributor. Let us know which way you want to go and we can talk about it.

2olds

The v-6 throttle cable will not reach the v-8.

Olds1971

THANKS that picture was right on what i needed!!!!!!!!. Sweet now I can finally finish that part. As far as a distributor ill post a picture of it today. How do you know if you have HEI? Is that with the coil right on top of it?

Intragration

The V6 throttle cable will reach the V8. In fact, my 455 is taller than a 350 AND I'm running a 4 bbl which has the connection further forward on the carburetor than a 2 bbl and it reaches fine. I can't imagine you're going to have a problem with this.

Yes, HEI has the coil in the middle of the distributor. If you're going to send pictures, the ideal would be to look inside the distributor, to see if there's an aftermarket setup or points in there.

2olds

Thats funny because it did not work when i did my 82 cutlass. Maybe i change it because it did not hook up to the carb its been 9 years ago.

Olds1971

It just looks like my 83s distributor besides no coil on top lol IDK what im looking for. cap looks same, router looks the same. I might stick with what I have. My funds lack a new distributor. I still need to find frame pads I wish the v6 frame pads would work