I had ceramic long tube headers on my 99 dakota R/T with around 12 to 1 iron head 410CID and those headers you could still hold your fingers on for a couple seconds immediately after getting back from running hard down the highway even before shutting off the engine, most headers I have seen will melt your skin instantly on contact after somethign like that. Under hood temps were much lower than most other header equipped cars. Something else I did on that one was I ran an airgap style intake but it would not have much access to cool air to flow under it so I removed all the webbing I could from the huge AC/Alternator bracket and ran a big mechanical fan (I normally run electric fans) to keep a steady stream of air flowing through there. I even glued a phenolic resin type plate to the bottom of the intake to keep the hot cam oil from heating the intake.

Other things I have thought about as far as ways to keep the air cool is to use plastic ducting instead of metal (Aluminum dryer ducting), you could strip all the paint off a metal air cleaner and ceramic coat that, obviously make sure you suck air from in front of the radiator not behind it.

Sometimes lots of little things add up to make a pretty significant difference.

I always wonder why nobody makes phenolic resin intake manifold gaskets for old motors, it would be a nice way to help keep heat out of the intake manifold when plastic intakes are not available.

Has anyone come up with a good way to run reverse cooling on a mopar engine yet?

I am gonna see if my local machine shop can put copper beryllium exhaust seats in an iron magnum head I am getting ready to put in my next MPG project... I had not thought about doing that.