Typical outer sheet metal is 19 gauge, but the larger trucks will have areas that use thicker (like the front fenders), so best to check with a set of calipers. For something with "tricky shapes", drawing quality steel would be your best bet, sometimes known as AKDQ, or aluminum killed drawing quality. 20 gauge is a bit too thin IMO.
Last edited by MPandC; 10/26/2015 2:22 PM.
