Make some basic sheet metal heat shields for your manifolds/headers.

Every single car and truck you could buy started running stamped sheetmetal heat shields several decades ago. They reflect radiant heat coming off the exhaust away from the rest of the compartment & down toward where air is flowing off the K frame and towards the floors. They work.

Before I made & installed mine, I couldn't even touch the underside of my air cleaner after driving the car. I just reuse the bottom left/right corner valve cover bolts to mount mine.

Who knew??? I didn't!

Sounds like a good idea. Have any pics you could share? Are these shields just flat plates that go over the headers or do they enclose the header tubes?

It was mentioned, I believe, but if you are running your timing at 32-34 this can cause the exhaust to get very hot.