I have gone to multiple auto parts store and cannot find high heat sealant. Where do you find this item and what is its' maximum temperature rating?

Hmm, last time I was at the Advance store they had the Permatex high heat copper in an aerosol can. Wonder why you can't find it? It should be something easy to find.

I've seen it at most automotive parts stores. They ususally keep it with the other silicone sealant's. The temp rating should be on the tube.

The highest temp. rated sealant that I have found is 650 deg. f. I believe that an exhaust manifold temp would exceed 650 .

Look at POR-15's Fire Seal 2000. Made for sealing up manifolds goes up to 2000F.

http://www.por15.com/puttys.html