Whos water pump did you use? I've had problems with cast fin high flow pumps in the past.
You should have lot of air flow with electric fans, is there a shroud on stock fan?
Any dumb reason your electric fans are fighting the stock fan?
FlowKooler Hi-Flow Mechanical Water Pumps 1679, is the one I used, stock pump acted the same way. The truck is a factory 400 big block, I just replaced the 3 core brass radiator with a 4 core aluminum radiator, the old radiator did the same thing, put a new OEM thermostatic fan clutch, and the shroud is stock, fan is about 3/4 inch from the radiator Electric fans are pushing stock fan is pulling.