water pumps

Currently have 8 blade pump w/viscous drive fan and stock t-stat. Hadn't thought about a bigger hole for the stat - I guess that would lower the pressure... I was under the impression that the 8 blade pump was the air conditioner unit but maybe that's just a cast iron water pump thing - all of them I've had were 8 blade units. I've also been told to toss the t-stat and just run a washer with a 5/8" center hole - is that big enough? Rember, this thing spends alot more time on the street than it does at the track. :scratch: