[Indiangoat]

The 455 seems to run a little cooler at freeway speeds with a standard T-stat instead of a high flow T-stat. Maybe there is such thing as too much radiator flow after all. I think the slightly smaller orifice of the standard T-stat reduced the extra flow that I gained by installing a hi-flow water pump while simultaneously minimizing the divider plate clearance. Maybe the slightly lower flow is allowing the cooler water on interior surfaces of the radiator to mix more efficiently with the hotter water in the middle of the flow.

The motor still creeps up to 220-230 at idle though. Ugh. Since this is probably not the result of a lean condition, I think I'll try a bigger fan and fan shroud to help pull air through the new aluminum radiator. Interestingly, it's harder to see through the new aluminum radiator than a standard 4 core desert cooler when looking directly though them. The horizontal fins on the aluminum radiator that run between the vertical tubes look serrated on the aluminum radiator which allows turbulent air to move up and down within the radiator as well as go directly through from front to back. I guess this engineering design helps provide more surface area on the fins for heat exchange. Still, it's harder to see through, and it may be harder for air to pass through. Thus, I guess I'll try a larger fan (19.5 inch) and fan shroud. If that doesn't work maybe a pusher fan will help.