When I was still using a Cleveland block with aluminum CHI cylinder heads, I bypassed the coolant fill tank and eliminated a lot of the cooling system restrictions. In my opinion, the original coolant flow design in a Pantera appears to be about as restrictive as it could get. I used a FlowKooler pump at that time and didn't seem to have a cavitation problem at high rpm. When I removed the Cleveland engine and went with an aluminum Fontana block with aluminum CHI heads, then engine is now considered a Clevor. The coolant lines come out of the front of the cylinder heads into a remote thermostat housing. The engine builder used an Edlebrock water pump for the new engine, which under normal or high performance street driving has done an excellent job of cooling my engine. My issue with what I have determined to be a cavitation problem showed up on the race track where my rpm is up at the 6000 range and tends to stays there. I don't track this car very often, but from my research on the Edlebrock pump it shows that they are not using an enclosed impellor design. The FlowKooler pump has 16 vanes and has an enclosed impellor, which helps to eliminate cavitation. I have worked on and been involved with pumps and cooling systems at the industrial level for over 40 years and have seen issues with cavitation, so I do have a working knowledge of pump design. I have owned my Pantera for 44 years and have tried a lot of different things to keep the engine cool, which living in southeastern Arizona isn't exactly easy when you are trying to drive the car in the warmer months.