MAHLE Original/Perfect Circle piston rings lead the way in ring technology and innovation for the Aftermarket – after all, MAHLE is the largest manufacturer of piston rings in the world. MAHLE Original/Perfect Circle rings are at the forefront of light vehicle piston ring technology. Extensive OE connections mean that MAHLE Original/Perfect Circle rings have the technological edge. Things like the CP-20™ oil ring, narrow compression rings, steel compression rings for gasoline engines, low-tension oil rings and coated compression rings for diesels all came from the OE. The MAHLE Original/Perfect Circle performance line proves time and again that it should be the ring of choice under every hood - regardless of the application. GM 305. Bore size: 3.736" Top ring: 5/64" cast Second ring: 5/64" cast Oil ring: 3/16" Stainless.
