Hastings "Tough Guy" Racing File-Fit Piston Ring Set - Bore Size: 4.155" Top Ring: 1/16", Second Ring: 1/16", Oil Ring: 3/16" - Oil Ring Tension: Low H777C05XXL Because these mufflers are so

Because these mufflers are so aggressive

1968-1974 Chevrolet K10 Suburban

600'' exhaust with AFR's hardened ductile iron interlocking seats

1994-2001 GMC Safari

Utilizing cool shell technology to minimize radiant heat from the muffler body

Hastings "Tough Guy" Racing File-Fit Piston Ring Set - Bore Size: 4.155" Top Ring: 1/16", Second Ring: 1/16", Oil Ring: 3/16" - Oil Ring Tension: Low H777C05XXL Because these mufflers are soHastings racing piston rings deliver race winning performance in even the most extreme applications. The low tension, low friction design provides unsurpassed combustion seating and exceptional sealing. Each set includes plasma moly, high tensile cast iron top rings; reverse twist, taper faced cast iron second rings, and choice of standard or low tension Flex Vent stainless steel oil control rings. Low tension oil rings make significant increases in