What is the difference between a fatboy and a heritage?

Biggest dif was the wheels.

FatBoy came with solid wheels, the Heritage came with spokes.

True, and most of the differences are just cosmetic. Seats have the studs in them, along with the standard matching saddlebags. The fenders are also different, the Heritage has more chrome trim on their front fenders and is more of a full fender. Front ends are the same and chassis is all the same, engines and all that. Basically just cosmetics!!