Just trim, the Impala has more trim on it, fancier interior, and three taillights per side, BelAir is a bit more stripped down and has two lights per side. Most everything will interchange between the two.
4 vs. 6 tailights. Let me tell you from experience that if you plan on going kustom and losing the trim, get the Biscuit/Bel Air
Its a bel air wagon. im gonna be getting it the first or second weekend in june. no cash out of pocket, im trading him a mini truck for the car.