The lower rad hose got a stainless spring in short order.

By increasing the diameter of the impeller you have increased the pressure that the pump can provide at any rpm. If the increased pressure causes the coolant to flow through flow restrictions, then flow will increase also. Both these additions increase the amount of power the pump eats.

R.

I've seen close to 10° temp drops using one of the pumps like a Flow Kooler w/ the plate on the impeller compared to a stock style pump. I've also used the Milodon version w/ success.

Keep in mind that these style of pumps require the use of a balance flow style thermostat like a Robert Shaw. They claim the added pressure from the pump will close a standard style thermostat.

UPDATE the car runs much cooler with the factory pump. I put about 100 miles since changing it and it definitely is more predictable from a cooling perspective. I did have to reduce the vacuum advance and overall timing to reduce ping. I conclude in my application that there is some trade offs but in the end I would rather not worry about it creeping into the 200 plus range. I would think I could get this to work by changing the thermostat, but I feel That electric fans are a better investment. The setup today fluctuates between 175-190 and feel I can level it out around 195 with airflow. I'm waiting for a hot day to do more experimenting.

FYI the application has a balance flow Milodon thermostat maybe it needs the Robert Shaw. This could be the root of the issue.

you can toss the stat for a day as the slow(er) warmup wont hurt you at all for (1) day & it will tell you if the stat is involved in the issue.