Looking for the correct fan clutch for the L78. I have the long water pump, new Harrison repo radiator, the repo GM 772 fan and the GM shroud. The GM fan clutch replacement, pn# 22050676 from Classic Muscle, is too long shaft-wise, going too deep in the shroud and is hitting the shroud on the bottom. So I need one with the shorter shaft. Any help would be appreciated. Thanks, John