Another overheating situation 63 Slant six

ah, good thought on the brackets, Ill give it a try.

I did run a hose through bottom inlet and water came out just as fast as I put it in.

Re Moof, it overheats under any conditions. Here in the Seattle area its in the 60's and it still overheats in less than 10 minutes or two miles.
Thought Id just go ahead and buy a new aluminum, and yeah, I've read ad nauseam, the back and forth on aluminum vs copper, but copper is $600 vs $200 for aluminum, but cant find one online right now. Champion is out of stock.

Thanks guys.