406 SBC IN 87 OLDS?

[tmoneymr2]

I'm sure this question has been asked a million times but searching through the forums is extremely time consuming. I'm planning on removing the factory olds 307 and TH200R4 transmission out of my 1987 olds cutlass supreme and swapping in a '78 406 small block chevy and 700R4 transmission anybody done this conversion or any small block chevy with a 700r4 before have any parts lists of what i will need or any heads up on problems i will encounter. Any help would be greatly appreciated. Also if anybody has a need for a 307 olds and 200R4 transmission the car is still running a driving perfect with them and they will be up for sale as soon as they are removed.

 

[Blake442]

It has been asked a million times, that's why we have these threads stickey'd at the very top of the forum.

Same principles apply going from 3.8 V6 or 307 V8 to a SBC...

http://www.gbodyforum.com/viewtopic.php?f=13&t=2020

http://www.gbodyforum.com/viewtopic.php?f=13&t=2485

http://www.gbodyforum.com/viewtopic.php?f=13&t=974

 

[tmoneymr2]

I understand those articles are from a V6 to a SBC I guess my next question would be do the V6 G-bodies and V8 G-bodies use the same cross members and transmission mounts. My other question would be is the 200R4 the same dimensions as a 700R4 the V6 to V8 swaps are helpful but I'm really wanting to know from somebody who has done the Olds V8 to Chevy V8 swap.

 

[drogg1]

God forbid you have to do any time consuming research work on your own.

The crossmember you have will depend on the transmission you have not the engine.

2004R's do not have the same dimensions as 700R4's. 2004R's are the same length as TH350's and THM200's but I believe they use a different crossmember and may require a frame extension depending on the model year of your original vehicle.

The links Blake provided are very useful in any engine swap if read through.

 

[stomis]

I'm sure this question has been asked a million times but searching through the forums is extremely time consuming. I'm planning on removing the factory olds 307 and TH200R4 transmission out of my 1987 olds cutlass supreme and swapping in a '78 406 small block chevy and 700R4 transmission anybody done this conversion or any small block chevy with a 700r4 before have any parts lists of what i will need or any heads up on problems i will encounter. Any help would be greatly appreciated. Also if anybody has a need for a 307 olds and 200R4 transmission the car is still running a driving perfect with them and they will be up for sale as soon as they are removed.

Its not possible dont event try.

 

[G-Body_Vet]

I say go for an Olds 350 or 403 and keep the 200-4R behind it. It's a bolt in deal and no mounts need to be changed. Besides, an Olds motor in and Olds is way cooler anyway.

 

[84sbcregal23deg]

its a very straightforward swap. you're going to need frame stands from a small block chevy V8 car (monte carlo, malibu, late model regal with 305, el camino etc..) and will also need the mounts to go with them. i wound up using moroso solid mounts (just look them up for a monte carlo) with a G-Force crossmember. I have a TH350, but just get the crossmember for a 700R4. You won't need the frame ext. piece that was mentioned earlier in the post as your car is an '87. Don't forget you'll need headers, an accessory set-up for the front of the engine, probably need to change your radiator hoses, run an exhaust under the car (or at least hook it up to your existing one if its in good shape and the engine is mild enough), most likely modify your driveshaft as the 700R4 is longer than your 2004R. Also does your car have a column shifter or a floor shifter? I'll be honest that ive never tried very hard to use column shifter linkage in a car with an engine swap, but if you were set on keeping it, that might have to be modified as well. Your V8 radiator should work pretty well and you might have to tweak the transmission cooler lines to fit right. is this new engine carbureted? I'm assuming it is, in which case (depending on your emissions regulations) you can get rid of just about the whole engine harness and computer. you will only need to save a few wires out of the entire harness. i ran aftermarket gauges in my car, so i was able to get rid of just about everything and run a few new wires for the senders. hope this helps your parts list! good luck

 

[83hurst-olds]

I would stick with the 200R4 unless it is going out or there is another reason to do so. IIRC all 200R4's are multi-bolt pattern. That way you won't have to mess with the transmission lines, crossmember, or shorten the drive shaft.

The SBC IIRC will have the fuel line in a different place than your 307. I had to slightly modify the "L" on my column shifter to make it work with the 700R4, BUT, I went from a 3 speed to a 4 speed so it may not be an issue from a 200R4 to a 700R4. I actually liked it having a 3 speed column because I could start the car in neutral positiion (which was actually overdrive). Since this car had louder exhaust than I intended, it was nice to be able to start it and roll out before I woke up the neighbors (I worked midnights at the time).

 

[Qdub24]

I swapped a SBC 350 w/a 700R4 into my 85 Cutlass back in '07. It's an easy swap, but I would keep my 200R4 trans in there if I were you. The 700R4s suck when you put them behind a high performance engine, or all the ones I've seen have sucked.

 

[tmoneymr2]

Thanks everybody for all the info. So far I have pieced together i'm gonna have to modify my crossmember, possiby change the motor mounts and have my driveshaft shortened.