[Cliff R]

"The schematic that I posted on line depicts the Blocks water Jackets being closed off, someone online, in the past mentioned a Pontiac mod. and posted on PY, are you familiar with coolant mod?"

I've seen the mods but have never done them here. As part of my learning curve (over 25 years part time and 20 more years full time) doing these things I figured out how to build one of these engines with tight squish, optimum compression for pump gas, and full control of timing/fuel curves so they NEVER even think about running hot, overheating, pinging on pump gas, etc. So no need to look for modifications to help a problem that doesn't exist.

The KEY to success with a running hot engine starts on the engine stand and making good choices for it. Once you figure out how to get it to turn heat production into making power vs dumping it into the engine coolant, EVERYTHING in that area gets a LOT better. Don't get me wrong here, early on I built a few of these engines that warmed up very quickly, and started "creeping" up past 180 degrees, then 190, and even past 200-210 at traffic lights. Then they would creep up steady cruising to and sometimes well past 200 degrees. Used to drive me nuts until I got better at the basics of engine building and making better choices for them.

Up until I figured all that out I did what I see countless others do on the Forums......look for ways to get rid of the heat like massive radiators, multiple fans, high flow water pumps, etc. When you do better with the basics you can cool one of these engines effectively with a stock water pump, stock radiator and factory clutch fan.

Getting the "basics" right resulted in the last three engines that powered my car not wanting to heat up at all and at times they would run so cool it was almost a PITA to get them up to temp. For example, drag racing in late Fall when the temps were getting below about 50 degrees I'd have to leave my engine running in staging lanes or it would "lay down" on the launch and not pull nearly as hard on the run. Fully warmed up and heat soaked it was flawless so I kept it that way on race days.

I'd also add that doing the SAME thing every time at the track has you going rounds vs getting put on the trailer and headed home, so staging the car right at 180 degrees was one of the variables I took out of the equation, and it proved to work quite well for me over the years........