I've done similar work to my LT-1. All the numbers match, but I redid the entire suspension with compsites and polyester, offset trailing arms so I could stuff 15 x 10 wheels with 275s in the rear. the big sneakers make a HUGE difference in the handling. Flat Flat Flat in the corners. The engine is stock save for headers and flowmaters, and MSD. the holley has been rejected on a Dyno and I am getting about 290 at the rear wheels (not bad for a '72). Plus clutch, Ac work, new clock, American Racing Torque Thrust, new weather stripping , etc etc. The paint is a good 10 foot job.