I've just bought a 351 windsor out of an 86 econline van. I'm in the process of taking off the fan, however, there is an extra ribbed circle peice on the front of the fan that I can't figure how to get off. I'm guessing its the heat sink. I've removed the bolts that connect the fan to it and I've also removed the bolts connecting to the water pump pulley. However, this front piece still won't come off. Does anyone have any clue how to remove this piece?