I've got a 454 stuffed into my 70 K5 by the previous owner. It has the original 4 row radiator and long water pump but no fan shroud. I'm about ready to fire this thing up but the 19 1/2" fan is toast. Here's the questions -- How big a fan does this need? Original clutch type, flex fan or electric fans against the grill? If belt driven fan, what shroud will match up, the original for K5 350, the one for 396/402BB or the one for 74 p/u engine came off? Not a lot of junk yards around here so its hard to find this stuff out first hand.