EFI Alchemy
I had what sounded like a metallic tinging underneath the valve covers of the TBSS, so I took it to Doc, Eurospec2, and Yellowbird1232 (BlueCajun5.3 helped as well) to let them work their magic, and boy did they... Almost immediately, they figured out the noise was coming from the header, and was most likely a bad header gasket... So they unbolted the header, pulled out the crappy gasket that was installed with my Kooks, and put a stock 6.0L gasket back in there... Simply comparing the two gaskets while I had them in hand was night and day... The one installed with my Kooks felt almost like paper, while the stock was metal and far more rigid... So note to people who install headers, USE THE STOCK GASKETS... And huge ups to all the guys at EFI Alchemy for doing this for me when I was in a pinch...