spacer

Hello everyone, Im currently rebuilding the engine of my Thunderbird. after i removed the carburator i found out that the spacer is milled to an angle. has this a specific reason ( hood clearence maybe) or has it something to do with the carburator itself?

Does a fan spacer (moving the stock fan closer to the radiator) with the stock shroud help draw more air through the radiator? Does a 6 blade fan help and is it noisy? Would a smaller pump pully help by spinning the water pump faster? Thanks