72 A/C 340 Demon fan/clutch space?

My 72 Demon 340 has only 2 1/2" of space from the front of the pulley to the face of the radiator core. I have a U S Radiator direct fit aluminum. I read some folks have 5" of space here? Where the hell am I losing 3" at. This is friggin crazy. Do I have a different year water pump when I built my motor? I thought all the 318 340 360 water pumps where the same. I think I bought a high volume Mopar stock pump, but do they all sit the same? And I cannot see this taking up 3" of space that I am looking for. Did the 72 Demon have something different to cool with. Also, it is suppose to have a clutch fan? How the heck is that going to fit. Does anybody on here have a stock 72 Demon A/C car they can compare notes with me on???