Hi, my 1993 STS failed me, the engine got all messed up, timing chain skipped a few notches, after 200K miles i'm thinking of letting it go, so I've spotted a 1996 STS with a bad transmission, would the tranny on my 1993(4T80-e)fit on the 1996 model?

Hmm, I think so. I put a 96 tranny in my 95 seville, I don't see why it wouldn't work the same way.