Running Hot on the Highway

Looks like you've got a lotta cubes there in that small block, and then the 3.91's too. Sounds like you're doing everything right, though. If it were mine, I'd probably throw an engine oil cooler on it as well and maybe a Dodge van (oversize) radiator. Unless you're going after the stone "sleeper" look. Keep in mind that the one thing you mentioned....slowing down the water pump helped a bit......I hope that water pump isn't cavitating with the super-high RPMs on the freeway. 3.91s are insane on the freeway without overdrive.