I wish I could answer those questions. The guy I bought it from didn't have much info. I am running pretty much straight anti freeze. I was told the stall was to big at 3800 and would cause overheating due to slippage. The fan is about 17" and is steel. The temp around here right now is about 70. The gauge will stay around 220 at highway speeds and stays below 200 when idling at about 1100 rpm. I think the blower is a 174 B&M. I am new to the hot rod scene, so I'm learning.
Thanks.