I have a 94 trans am with a 383. mild cam and d1sc procharger. Long tubes to single cat back exhaust. My question is

Can anyone tell me what the normal egt should be at idle at the headers? I am reading about 550-600 degrees f at the first bend of each pipe on the headers. The headers are coated. I would like to get them cooler. Dont know if this can be done with tuning or what. Any ideas?

Thanks

 

Exhaust wrap.
A ceramic coating will slow the transfer of heat, but it probably won't run any cooler since it will still saturate to the same temperature.

 

Wont that stuff damage the headers?