If I were on a $2000 budget and were trying to build a smallblock to move 4800lbs. , I would not be thinking of a 350 or a 383. It would be a 400 bored whatever it needed,but not more than .060 ---So you end up with 406 to 412 inches. A lot more torque ,down low where you need it to get that kind of weight moving. The old saying , there is no replacment ,for displacment is especially true with a heavy vehicle.