[wildwilly4x4]

Sounds like a plan. I may order up some parts tonight for some experimentation! I'll keep up with the thread to show progress. I know idling with a/c in traffic makes this 8.1 get up in the 220+ temps fairly quick. Then it doesnt want to run good until i can either get the rpm up above 1500, or back at cruising speed. The heads must heat soak pretty bad on it, as you can feel it spark knock. The old stock 454 acted the same way. Mech fan just doesnt move enough air at idle. Even with two elec. fans it doesnt keep up. The full flow of hot h2o to the cold side of radiator is the only culprit i can come up with. All cooling system is in perfect condition, fan clutch, 4 row diesel sized radiator, fan shroud intact and hood shape.