If you'd provide Vehicle Identification Numbers (VINs) & pics (the more the better, ESPECIALLY of the RPO stickers on the underside of the trunklid!), we'd have even more and much better info to help you make your choice.
Based on the very little info above, I think I'd get the 93 if I was interested in changing the engine to any Gen 3 or 4 6.0L V8 OR 6.2L V8.
6.0L V8s: LQ4, LQ9, L76, L77, LS2
6.2L V8s: L92, L9H, L94, L99, LS3
Since I personally would not get into swapping upgraded engines & transmissions on a car old enough to rent another car, I'd get the 96 myself, though these days I'd probably prefer a Roadmaster or a Fleetwood over a Caprice.
1g1bl82p7rr127841 … Rust In Pieces, Rest In Peace …
They are NOT Lying to You
You are NOT Lying to Yourself
You are Being Lied to - BY Your Self
… Alone aka The Last Psychiatrist