Just my here but i'm totally done with headers. My 69 charger r/t stock 440, had headers, they leak both at the head and the studs (coolant), higher underhood temps, too much heat for the starter, and they are a TOTAL PAIN IN THE ANUS TO GET IN/OUT. So i got a used set of the HP manifolds and a TTi 2.5 with h-pipe, installed them (which was so easy it wasn't funny, i did it twice just because it didn't feel right!!!!) and the car actually runs MUCH better, i did'nt notice a performance decrease at all. Just for the ease of working with them, and how much eaiser it is to work on the car (plugs, starter, steering box, ect....) i will never run headers again!.