C3 Corvette 1968-1982 Long SystemARH C3 Corvette header systems are now available for conventional Small Block applications. Maintaining our tradition for outstanding 100% US made quality, our C3 Small Block headers are available with 1 5 8", 1 3 4" or 1 7 8" primaries to accommodate your desired application. Our C3 Long System includes our C3 headers, leak free ball socket connections and connection pipes that extend through the circular openings of the transmissions cross member.