Bob:
The '57 312 was factory rated at 245 HP, the '56 was 225HP. The differences are better heads with bigger intake valves, better camshaft, different intake with the late style Holley carb, better distributor, bigger exhaust manifolds. The same engine with 2-4 barrels made 270 HP.
The supercharged engine was under rated at 300 HP. Parts that are different from the 245 HP are: cylinder heads, intake manifold, carb, distributor, camshaft, valve springs, pushrods, crankshaft damper/pulley, fuel pump and fuel filter. I probably left out something. Also unique are the supercharger, mounting bracket, belt drive components, inlet and pressure hoses, carb, carb bonnet, and air filter. With maybe less than 1800 cars and T-Birds so equipped, most of which were circle trackers, the parts are very, very rare. A pair of heads recently sold for about $4000 (though there are truck heads that make a satisfactory substitute), a bracket recently was advertised on this site for $400 and quickly got a response. I figure it sold at that bargain price. I have seen fuel pumps advertised in the $100 range for used ones. Used blowers are in the $1500 range, most need rebuilt, and original VR parts have been out of production since about '75. I'm not trying to scare you off, but your parts search will be extensive and expensive. Maybe you got enough out of your Shelby to finance this project. The easiest way to get all the parts is to buy a car so equipped, restored ones are approaching 6 figures, maybe more.
John - "The Hoosier Hurricane"
