Please no offense. This may sound a bit harsh, and I apologize for that. But why restore a '71 Grand Prix? Um, it's a rather "unfortunate looking" car. In my humble opinion anyway. A 1971 Lemans or GTO looks much better. Lemans is the same basic car as a GTO (the GTO just had a different grille and bigger engines). In fact, So Cal Speed shop just restored an early
70's Lemans for a show on the Discovery channel. They converted the Lemans to a GTO (new grille, new 455 Super Duty engine, new GTO badging).
I just think there are a lot better looking GM cars from that era. Chevys: Camaro, Chevelle, Impala, Nova. Pontiac: Lemans, GTO, Firebird, Trans-Am Olds: 442, Cutlass. On the Mopar side: Dart Swinger, Challenger/Barracuda, Charger, Roadrunner, etc.. Even the Dusters/Dart Swingers look better than a 1971 Grand Prix and these 2 mopars can still be had pretty cheaply. On the Ford side, I find the Mustangs from this era kind of ugly too.
I know a local guy who has like a 1975 Pontiac GTO (same body as a Chevy Nova). He had it painted nice shiny black. It's not totally original. It has nice aftermarket chrome rims and more modern GTO stickers (I assume different than stock; looks newer to me). The stickers are brighter and bigger than the original GTO badging. It's got a nice sounding rumbling V8. Cool car. But if you like the '71 Grand Prix, I guess stick with it.