You would need the Motor City Resin's 74 Econoline kit, and an MPC Ford Stunt Van for the engine, wheels, tires, suspension and exhaust. Then just have someone reszize the decals that come in the 1/20 kit.
Been seriously thinking about doing it!
I suspect he meant for Round2 to retool it in 1/25, not make your own. I'd buy one in 1/25, but 1/20 puts me off.