Thanks for this info. I looked at the two pulleys, and they appear to be roughly the same size, about 6-5/8". Any recommendation on size, and a vendor? I looked at Classic Industries and they only have the 6-5/8 pulley. They have the 160 high flow stat, so I'll get one of those.
Yeah that's 1:1. That could be some of the issue. I would put up a wanted ad in the classified section asking for a water pump pulley smaller than 6 5/8. Someone has something.