TexasGunner

I picked up my (new to me) engine today. The seller told me that it may have came out of a 71 cutlass. Strange thing is that a 400 transmission was bolted on to a 350 from the factory. Here are a couple pics that I took. I think the number near the water pump read: 395558 2 The head reads 7 8A. Can someone tell any info. Thanks.

Bluevista

Go to "Tech Tools" at the top of the page then click on "Oldsmobile Tech" and it has all the info to do engine and head indentification.
Why would it be strange to have a Turbo 400 transmission bolted on to a 350 engine at the factory?? I may be mistaken but I'm sure my old '71 Vista Cruiser came that way.

TexasGunner

Forgive my newbie experience, but I thought that 350 Rockets came only with TH350 transmissions and 455s came with TH400 transmissions.

svnt442

I had a 72 that was a 350/TH400 combo. It was all about the boxes that were checked at the time of order.

That is a 350 for sure. If you want to know the year of the car it came out of for sure you'll want to look at the machined pad just below the cylinder head on the left side of the engine just under that 7A on the head. there should be some stamped numbers/letters there unless it is a warranty block that wasn't re-stamped like it was supposed to be. If it's a 71 it should read 31MXXXXXX and 72 would be 32MXXXXXX.
The M is the plant it was manufactured in and could be one of a few different letters and the X's would match the last 6 of the car it came out of.

TexasGunner

Thanks svnt442 and Bluevista

442Harv

I had a 72 350 VC. I thought it had a 400, but when I took it out to repair, it was a 375, which is a 400 with a smaller tail shaft, same size as a 350 or 4SP. I think that is probably used a lot on 350 motors.

joe_padavano

Beat me to it, Harv.

TexasGunner

I tried sticking my old driveshaft that came with my car and it does not fit. The old drive shaft was for a TH350. The end shaft spline/gear of the new trans is too big to fit into the driveshaft slip yoke. I will clean up the trans later today and look for some casting numbers.

halfmoontrail

I'm almost positive that the TH375/TH400 yokes are the same. However, the long tail TH400's have a longer yoke, IIRC.
Steve

Octania

Ah, that might be the elusive "TH398 & 5/8" !

Used mainly on SOLID MAIN WEB 350's of the early 70's, but not too early.
Late June thru early August 1971 only.



But seriously, looks like you have a 1971 350 and TH400.
A good start.