Cold exhaust, hot valve cover.

I’m in the camp that wouldn’t be going nuts to solve anything until I had the temp gun in my hand.

Also, FWIW, I was running 10’s@3650lbs with a 906 headed 448 using an ootb Torker II in 1995.
I’ve used a number of them through the years....... never had any running “issues” with one.

It might be worth spraying carb cleaner or something around where the manifold seals to the heads...... top and bottom side to check for leaks.