Doc is your cooling system completely clean? I was fighting a hot running highway condition and I finally took a good look inside my radiator and it was about half clogged with scale from my old block. I installed a coolant filter in the upper hose and it filled up 3 times and now my car runs low 180's all the time. I have the Flow Cooler pump, 440 source repo pulleys, 26" aluminum ECP rad, 6 blade MP viscous fan, Mancini pump housing, Mr.gasket 160 high flow stat. Once I got the block flushed clean with Evapo-Rust and pressure washed the rad its all good thumbs

Gus beer

64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60