1980oldscuttnewbie

I have a 1980 cuttlass with a 4.3L V8 and what I think I've heard is a TH200? How hard is it to put in a 350, and what transmissions can I put in aswell?
Thanks

joe_padavano

There were three different 4.3 liter V8s built by GM: The 260 cu in Olds, the 262 cu in Chevy, and the 265 Pontiac. Each is completely different, so be sure of what you have. I'm pretty sure only the 260 Olds was factory available in the Cutlass, so let's assume that's what's in there. A 350 Olds is externally identical and is a bolt-in swap. Use the motor mounts, exhaust manifolds, water pump, and accessory brackets from the 260 and you'll have zero problems. This is about the easiest swap going. Note that a 403 Olds is also externally identical and will also drop in.

A TH350 trans is also a bolt-in.

Oldsguy

Joe, I interperetted his question to be asking about the TH350. My counter question to him would be, has the transmission in your car failed in some way? If not, why are you looking to replace it?

joe_padavano

That was also my first reaction, but the title of the post is "engine and transmission swap".

1980oldscuttnewbie

will the transmission that is in the car work and hold up to a 350? If I run a lot of horsepower will the rear end hold up aswell?

Oldsguy

Joe, I missed that, yah you were right then. Sorry.

joe_padavano

The TH200 and 7.5" rear axle will both grenade if you get any serious HP and traction.

Jim's rare 80

Hey. This is a thread with my name on it. (sort of) I have done the swap you are looking at doing, even the same car. As said earlier, an Olds 350 or 403 is a bolt-in. A th350 tranny is as well. My opinion, a 350/350 combo would be your best bet. 403's have more limits on what you can do to the block. Also, bigger engine means bigger tranny, here's why. Bought car in May 98. Did engine swap in July 98. Put in a fresh 70 350 W31, with #6 heads, to the 200 tranny. All of a sudden Jan, 99. Had to install a th400 tranny. (It's the one I had, and I had to modify trans bracket for that) Now, untill last summer, I was still running the stock 2:29 rear axle. No issues. I am changing it this year in favor of a 3:73 ratio, as I am in the middle of a frame-off resto, and it won't be a daily driver any more. Check out my pics in the gallery. I'm sure we'll be adding to this thread. PM me if you want.
Jim.

Oldsguy

Nice looking frame. I like clean painted metal, it makes me horripulate.

Jim's rare 80

Cool, but just for the record, that's an acid bath, and powder coated frame. Nothin' but the best for my baby. Wife's response

Jim's rare 80

Hey, if painted metal makes you horripulate, what does powder coated metal do to you? Just curious.

Oldsguy

Oooooo, don't even ask!