Our 65 R&D Mustang coupe has full functioning interior, two layers of sound deadening, heater, tunes, and an iron block/head engine. Weighs 3090lbs.
I have been talking with our regional rules board and members about a tire size/weight limitations, as I know this can turn into check book warfare pretty quickly. I'd rather have stricter rules that get loosened, vice the other way around. Best way to scare off competitors is to constantly strangle out purpose built cars that disenfranchised your intended participant crowd in the first place.