I know that the buick 231 came in older (pre '75) CJs, but did it ever come in the later ones? If not, are the motor mounts the same? I.E., could you bolt a late model 3.8 in or would you have to move stuff around? Also, what auto trans goes between a GM 60 degree and a 23 spline t-case? Say, from a 3.8 to an NP249? 2004R? I know the S10s had 2.8s (60 degree) with 2004Rs and NP231s, but I think they are 21 spline? BTW, I know there are better swaps than 3.8s, 2004Rs, and NP249s for 'wheeling, but I'm up to something.

Originally posted by zorr0
I know that the buick 231 came in older (pre '75) CJs, but did it ever come in the later ones? If not, are the motor mounts the same? I.E., could you bolt a late model 3.8 in or would you have to move stuff around? Also, what auto trans goes between a GM 60 degree and a 23 spline t-case? Say, from a 3.8 to an NP249? 2004R? I know the S10s had 2.8s (60 degree) with 2004Rs and NP231s, but I think they are 21 spline? BTW, I know there are better swaps than 3.8s, 2004Rs, and NP249s for 'wheeling, but I'm up to something.

Buick 225's were in 65 to 71 CJ5's. Same engine mount as 231's until they went to FWD. That being said, the 200r4's you're talking about use a chevy bellhousing pattern, while the block uses a BOP (Buick, Olds, Pontiac) pattern. Which are different and wont work. You can pretty easily swap in a BOP TH350 though. Or you might be able to make/get an adaptor plate. BTW the 231's not bad at all for wheelin.

I did not know that they were two different bellhousing patterns. You can't switch just the bh, can you? The other question was, though, how different are the motor mounts in old CJs and post-'75 CJs. I mean, if you get Buick 231 engine mounts for a '72 CJ-5 and try to plop a 3.8 in to a '81 CJ, does everything line up, or is it completely different? Also, is the NP249 a 23 spline input? I'm not sure but I think it is. How hard is it to get a 23 spline output TH350. Advance Adapters, I assume. How about a 23 spline 2004r? Is there a way to do this? TIA.

ttt