Here’s my 97 cutlass supreme sl ls4 swap progress over this last year. This has not been an easy swap whatsoever, we have had far too many hurdles but we’re still goin’.    First off alternator and balancer clearance was a problem, so we had to cut and plate into my strut tower about 2 inches. factory subframe wasn’t gonna cut it so we had 2 options: newer Impala subrame which around here costed a fortune, or custom subframe, which we ended building and turned out not too shabby