Its coming from a 79 cutlass supremeThe Buick 231 and the Oldsmobile 260 are not a direct swap and you can't use anything off the V6 for the V8.
If I were going to trouble of swapping a V8 in place of V6 I would look for at least a 350 so you actually are adding power.
I really need thr transmissionIts coming from a 79 cutlass supreme
If you can get everything off a donor car it would make the swap easier but the 260 was designed as a reliable economy engine and that is all it is really good for, if you are looking for a big power increase go with something bigger.
GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.