So a 700R4 (or TH350) would still bolt up to it or would an adapter be necessary?
No big blocks for me buddy, thanks anyway. Arent the bell housings different for a big block?
The LS engines have a differant bolt pattern than old the common ran forever Chevy bell housing. So an adapter would be needed. There are differant options there though. Its expensive but there are aftermarket companies that convert cases to removeable bellhousings, then you bolt on the newer bell housing and should be good to go.
Big Block, Small Block, 90 degree V6 and Chevy I6 all share the same Bell housing for years and years and years. That all changed when the 5.3 and 6.0 came out. And on the 8.1 BB, I am not certain. I have a feeling its probably the same old bell housing. Not 100% sure on that one.