swapping a 3.8L v6 for a 350 sbo in an 85 cutlass

[bill]

Hey fellas,
Just need some helpful tips on my motor swap. I need to clear up some iffy advice or opinions that have been given to me from outside sources about this swap. One of them says that the 200 metric crossmember will match up to my 350 turbo transmission. another says I all my gauges will work with the 70 model 350 without the computer. and I just need to know what header will fit the #6 heads and not cause problems with clearance, clarence...lol.?.! thanks for your advice! please feel free to offer your opinions or relay your experiences, ie distributors, carbs, headers, ect.
Bill

 

[Blake442]

Any g-body SBO headers will work. There's a number of vendors that sell them and they will fit any of the 260, 307, 350, or 403 V8's. Just make sure you're ordering the correct ones for an Olds, and not a Chev.

You might want to consider an aftermarket trans crossmember that will allow for the easy clearance of true dual exhaust. Otherwise you're stuck trying to either modify or cheat around a stock one. It's worth the money.
Try http://www.crossmembers.com I've bought from them for both my 442 and my Cutlass wagon and have been very pleased.

Your gauges will still work without the computer, but you will have to switch the sending units on the 350 to the ones for a 307. Any local auto parts store should have them in stock. You'll also have to dick around with the engine wiring harness a bit, as things on the V6's are in different locations as the V8's... I had to unwrap/rewrap some of it to accomodate for it, but it's not too hard.

Hope that helps a bit.

 

[beeterolds]

you need to remove the 3.8 frame pads and install Olds pads.. they are sorta hard to find and a bit pricey.. simply cause you need to pull the motor to remove them!!

you need to move the wiring harness and battery to the driver side, you need a new fan shroud and radiator.. and fab up something with the exhaust. my car originally had a v6 but i moved up to a 403..then ultimately to my 455 😀

 

[dougfather]

Here's a link to a site where someone swapped the 231 V6 to a 403 Olds.

http://www.robertpowersmotorsports.com/G-bodyV6-V8.html

 

[82cutty]

I did the V-6 to V-8 swap to an 84 in 2000 to an Olds 350, and I just did the swap to a Chevy V-8 2 months ago in an 82 Cutlass.... For your Olds engine you will need the frame pads and they should be avaliable from GM, I got my Chevy ones from GM for about 30 bucks a piece. I also got my shroud from GM for about 128 bucks, but it isnt the same one as original, had to order mine for a Monte. The Olds was discontinued and none anywhere in the US. As for headers I went with Flowtech and they do not fit well with the auto transmission, the clear all the frame stuff fine. I had to grind the right ear off the transmission and it still hits the trans pan slightly. I got the G-Force crossmember thru Summit, it is a nice piece. The left side is off a bit towards the transmission and you need to have a real hard bend to get thru it, the pass side is dead on with the header. As for the gauges the oriiginal senders should work for the idiot lights, unless you have gauge sender units. As for the wiring, all the major wires you need minus the computer come from the left side. With the Chevy I was lucky the V-6 starter wires were on the same side and all my asseceries were on the left side. On the Olds I used a donor harness from the car I pulled motor from and re attached the wires to the outside fuse block. It was a lot of work but real clean when done. You will need to run a wire from your alternator to the battery in some fashion and you will have the pink wire from the 2 pin harness loop to the back stud on the alternator. There is no horn relay outside and the charge wire runs to the starter thru the computer I believe on the V-6. Feel free to PM me about questions...... Been thru it all and it is still fresh in my head if you have questions.

Steve

 

[Uncletruck]

I'll be doing this swap soon, 231 V6 to 350 Olds, this is good info to read and I'm printing it out and keeping it in a folder. Luckily this is going in to my '78 LeMans, and the 350 was pulled from a '79 Delta 88, and I removed everything from the Delta I saw that I might possibly need to do this. No A/C and no computer stuff to fart with. I did buy new engine mounts, found aftermarket stuff there. Biggest expense I see is the exhaust system which I'm having custom built front to back. I'm going to keep the sleeper look single exhaust original style, only using a little bit wider than stock exhaust plumbing. That's the only part that will remotely show on the exterior, and it's not going to be a rumbly Flowmaster sound. Engine will remain all stock GM components, (No lopey cam, no Holley carb or chrome air filter), will feed power through simple reliable TH350.

-UT-