The Chevelle that Dwayne Johnson drives in the film is a 1971 or 1972 model (as evidenced by the dual taillights), but the front is from the 1970 model (as evidenced by headlights and grille). Also, although the car is badged with the SS (Super Sport) logo, it is in fact a Malibu edition Chevelle as evidenced by the sweep style dash - SS Chevelles have round gauges.
The snub nose revolver that Driver (Dwayne Johnson) is shooting is a Ruger 2.5" barrel, Super Redhawk in .454 Casull, Cat.# KSRH-2454, Mod.# 5301. Killer (Oliver Jackson-Cohen) uses an H&K P30 with silencer, and a Glock without silencer. Cop (Billy Bob Thornton) uses a Glock.
When Killer is in his car staking out the old man's apartment, you hear the sound of him cocking his semi auto pistol, which takes two hands. As this takes place, you see him put the gun into his holster with one hand.