If its a street rod, you wont have a very big radiator and if you live in the south you wont be able to run more than about 450hp threw a downflow 15x20 radiator in the summer. i drive mine in the winter and fall when air temp is down, with the boost turned up on pump gas, the motor makes 700hp easy with 12 or more pounds of boost. During the summer its underdriven and I might get 4-5 lbs out of the 6-71, maybe about 400hp
Your motor should make around 650-700hp also with about 10 or so lbs of boost