451 small block?
W/1-5/8 headers?
W/1-5/8 headers?
Exhaust manifolds can also run quick. Cam timing and exhaust layout are critical. In general, a bigger header should in most cases provide better performance. This thread makes me wonder about several things starting with what are guys giving up with the smaller header? Then what is the details of there combo to run as quick as they do with the small header.