Over time all internal engine wear surfaces become worn. This is true for crankshaft journals, connecting rods, camshaft lobes, piston rings, bearings, etc. When rebuilding a worn out engine youll need to replace them all in order to regain the engines original performance. And, lets face it, Jeeps need all the power we can get. Omix offers new high quality replacement engine parts to get your Jeep back on the road. This replacement piston ring set fits 79 - 83 CJ5, 79 - 86 CJ7, 81 - 86 CJ8 Scrambler, 87 - 90 Wrangler YJ, 79 - 83 Cherokee Wagoneer SJ, 79 - 87 J - Series Trucks, 86 - 90 Comanche MJ and 84 - 86 Grand Wagoneer SJ models with 3.8 or 4.2 liter engines with 0.030 - in. over - bore. One set does one engine. Replaces OE 4485572.030