Just an FYI to readers since you've already ordered the parts: You can order a one or two shiv pully from Summit or others that fits a Chev V8. The short shaft pulley gives more than adequate space in my AD application. Once you have the pulley you need to press the mounting flange further onto the pump shaft by 1.1" IIRC, check this by measuring the difference between the six cylinder pulley and the V8 pulley. I have done this on a couple of pumps successfully. Do not press the flange too far because its difficult to press it back the other way and too much of an interference fit to use a gear puller.
When you're done relocating the flange, cut off the excess shaft it it seems necessary or desirable. Then, on AD trucks, You'll have to drill some extra holes in the radiator mounting frame to lower the radiator enough so the fan doesn't hit the radiator's water inlet at the bottom. I used a 6-blade, high-pitch 16" truck fan. Bigger fan will hit the lower hose. This setup has run for a couple decades with minimal overheating problems, certainly no worse than when it was stock with the high-mount fan and pulling a ton of hay up a steep grade on a hot day.
