Carl and I have been battling this in our buggies too.
Here are the things I have done in the past and they have helped a lot.
1) I just lined all of the panels around the motor with insulation. I bought a kind that is basically rubber sticky stuff with aluminum foil on one side. It dropped the heat (ir tested) 80 degrees per panel.
2) I have a ceramic coated muffler to install. On Kate and the Bash Buggy I ceramic coated the exhaust and it was a huge help. In fact, I was shooting temps and my ceramic headers are 50* cooler than the Y pipe they dump into.
3) Shield the muffler if possible.
4) Radiator in the rear with all of the air pushing away from you.
5) I may ad a tranny hump and insulate it. The hottest thing on my buggy is the bellhousing. It is about 250* once the tranny heats up to operating temps.
When we went to Colorado the heat in the front was bad on the road when the wind was blowing through and pushing it on us. Crawling it is not as bad. I attribute it to not having all of that aluminum interior to radiate heat.
The blanket idea the hillbilly had is one I had as well.
