I have a 73 chevy 350 engine I have built to run about 300 - 325HP. I am putting it in a late 40's vehicle and will have to change the ram horns due to steering box issues. A friend has a set of 55/56 Corvette manifolds that will work perfectly but believe they came off a 265 and appear to have a slightly smaller internal diameter. My question is will the difference in size cause a restriction problem with the 350? Would polishing the inside make a noticeable difference on the smaller exhaust. Because of the layout I would have to have custom headers made so I am looking at the difference of swapping with my friend for no cash or spending several hundred dollars. The vehicle is intended to be a driver and local car show participant only.