Do you want to run with stock carb/distrutor and emissions system? A stock 350/403SHOULD run fine but use the 350/403 exhaust manifolds, swirl 307 manifolds are too restrictive, get dual exhaust and eliminate the air injection system. If everything is blocked off, the car will run fine, probably better without it. Even the mid/late 70's 350 had the same hp but also 20-25 ft/lbs of torque over the 307 HO motors.
