Join Date: Apr 2003
Location: Terre Haute, IN
I'm not sure how an exhaust header could influence the EGT's beyond a leak. Certainly, you can add coating inside or out, but 304, 321 or 3XX are all going to radiate similar temperatures whether not the color they radiate is the same or different. 421 Pontiacs had aluminum manifolds for drag racing.....they are going to glow and melt much sooner, but not necessarily get any hotter than a set of Iconel headers.
Though I don't own a set of these headers, I would just check a few other things before I threw the headers under the carpet. Take surface temp or EGT and see where your really at...I don't know if color emmited is reflective or diagnostic. Certainly check timing and AFR's as Merv as suggested. You might have been on the fence before. You obviously/probably changed to headers for some reason. Probably to change/increase air flow...therefore your engine has a different set of parameters. Just my .02
72 RS spirit 2.7mfi, 73 3.2 Hotrod on steelies, 76 993 3.3efi TT, 86 trackrat, 91 C4s widebody,02 OLA winning 6GT2, 07 997TT, 70 914 v8