Rather than edit the old post, I'll put it here, so that there's less confusion. I did not add in the length for the water pump pulley thickness. Add another 1/8" for that. So, 1-1/16" would work. I have a big block that uses bolts. I can't put the fan and clutch on if there are studs because the fan clutch is too close to the radiator. It's a severe duty job that really pulls some air. Getting those bolts started is a real delight.

I'm glad I don't have to do it too often.