Great information. Thanks very much. I will make a few phone calls. I already mounted the napa pump and would have used it if the pulleys had lined up. The napa shaft is longer by about 1/4". I am lucky that the truck has dual thermostat controlled electric fans, so the fan mount isn't the most important part. They were auxilliary fans as the truck was from a hot and hilly area at the Columbia River Gorge.
'92 F350 4x4 dual wheel flatbed truck. 7.3IDI, 5 sp man tran. '59 F350 nine foot flareside with cummins 6AT, '47 2 ton stake with 8rt, '47 tonner panel, 47 tonner pickup,'46 tonner cab/chassis, 47 1/2 ton pickup,'46 1/2 ton panel. Antique one lung flywheel engines.