I don't want to be a naysayer but unless that 302 is in really bad shape, I can't see the advantage of going through all that work swapping it for a 351. You obviously have no idea what a job it is doing a shade tree engine swap on a van. I've done them, and I would rather do four swaps on a pick up, then one on a van. If your just looking to get a little more Wheaties out of your ride and the 302 is fairly sound, you should consider just doing some mods on that motor.