I snaped a few pics , if i can post them to the right size i'll post them. anyways the nose on one of the pumps had alot more meat to it, the other was more narrow so pump housing itself is a tad different thats why i got diff measurements from hub to casting, i took the one off the engine and had them both side by side they are exactly he same and hubs were press on equally as well one was a six blade the other eight high flow.
My pullys were not lining up either Chryco,this is how i got it when purchased the engine, wrong pullys at least not matching. i had a extra A/C bottom pully and matching top pully so every thing lines as far as fan and crank pully goes.