Reading this gives me all the good feels. I am literally doing an almost identical swap as you. I'm gathering the last few parts needed right now before I start tearing into mine. It's my daily driver so I am trying to keep my down time to a minimum. I have a 2wd LWB 1978 GMC C15 that I am...
You should check out Tejas Steel Works. They make an aluminum fan shroud that bolts to the existing radiator support for the stock heavy duty radiator and the shroud accommodates two electric fans from a 93 to 97 Camaro. Those fans will keep that bad boy cool with no problem.