For C4 Corvette owners, American Racing Headers has finally answered the call. Your long awaited C4 systems are here! With features you'd expect from ARH including all 100% US made 304 S/S construction, 3/8" thick flanges with hand ported inlets, merge collectors with scavenger spikes, your choice of 1-3/4" or stepped 1-3/4" X 1-7/8" prim