Karlos,
First thanks for the feedback. I did pick up on the starter grunting when warm so my first clue she has plenty of timing, BTW stroke the throttle 1 time before you hit the starter so it will gain a little head start before clearing it's throat and trying to start.
WOW... 7" at 800 RPM. That seems low Karlos. Try closing @ corner A/F screw to prove it kills engine. I would look for leak or carb issues. call me
I see by the measurements you gave that the waterpump is UNDERDRIVEN and I really that is a problem in Phoenix heat. Now you are running the pump 15.4% slower than the crank RPM. Reverse the diameters to gain a 15% OVERDRIVEN w/p and you will gain a 30 percent increase in coolant flow. She will then move enough coolant to pressurize the cooling system (ya need 8PSI or >) to xfer heat into the coolant efficiently. Yep I know that is a HP loss but if you want to drive her on the street this makes a BBC live when 110* or more in our neck of the woods.
The pulley source for anything is here. The small W/P diameter is harder to find aftermarket but tell the guy what diameters you are trying to get. You don't need NCRS parts just a combo that will work for your hot rod.
65-68 Corvette "NOS" 108 BIG BLOCK PULLEY 3863108 crank shaft New old stock 8" | eBay