I was thinking about this the other day with a friend and we couldn't come up to an agreement for which one is better. I think SS would be a better header heat shield since it can resist much higher temps and doesn't absorb heat as fast as an Aluminum.. now I know Aluminum is used for a lot of shields and we all know aluminum get rids of heat a lot faster, but in the case of a heat shield you don't want the heat to dissipate in to the engine bay, but stay under the shield.

So which would be better? what do you guys think?

 

Stainless would be the best choice for basically the reasons you stated. You could also just use mild steel and spray it with BBQ paint.

 

I would use aluminum for lightness and ease of workability, and then put a layer of heat-resistant fiberglass matting in there to do the work of the heat shield. DEI makes a 4' x 3' sheet of insulating and refective matting for about $50, and that is enough material to make a lot of heat shields:

http://store.summitracing.com/...10682

 

good ideas. Thanks.