Filled block on the street?

GT451 said

My .030 over 318 was filled to top of soft plugs by the previous owner and it runs hot any time I'm not moving 35+ mph. I have a 8qt pan and have tried several different water pump/fan combos, including mechanical and electric of each. No matter, it always creeps to +/- 220 in traffic, 190 moving down the road.

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Like a few guys just said a low-speed cooling issue is due to bad airflow through the radiator and/or coolant flow. If the engine was putting out too much heat in general it would run hot no matter what. Put a nice big electric fan like one off a modern sedan mounted with a shroud and a couple inches back from the radiator with the shroud sealed all the way around the best you can. If you do pull a fan off a junkyard newer car for instance try to recreate the setup that was in that car, modern cars make TONS of heat and engineers spend lots of time and money figuring out how to squeeze air through those tight-packed engine bays.

FWIW the big factory Mopar viscous-drive fan and shroud setup is tough to beat I have a 10.5:1 360 that only gets up around 200* if I'm stuck in traffic on a sunny 100* day, and that's with a 180* thermostat which actually puts MORE strain on the cooling system.