We are by far the best value. They go on mowers and pulling tractors all over the world! This is for ALL the K301 and M12 Kohler engines, which means that it will fit all the K301and M12 engines regardless of the suffix. CUSTOMIZED TO MEET YOUR ENGINE REBUILD NEEDS….. KIT INCLUDES THE FOLLOWING. 1- New Piston: PISTON COMES IN choice of: Standard. 040 over, with Chrome Piston Rings. Wrist pin and Keepers. CONNECTING ROD COMES IN choice of: Standard, 010 or 020 undersized. Intake Valve 1.372. Exhaust Value 1.125. 12hp K301 These measurements are not for machine shop reference. The machine shop must have the new piston before they can bore the cylinder. Anybody can Rebuild a Kohler engine themselves. Kohler INSTRUCTION manual ON HOW TO REBUILD YOUR KOHLER ENGINE off the Kohlerengines dot com Web site FREE! I will also give the instructions on how to properly install your connecting rod. (Oil hole goes towards the cam) The most common reason for premature engine failure on your rebuilt engine is an improper rod installation. In my other auctions, I also offer high. Thanks, Kevin Thanks For Looking! The item “MASTER REBUILD Kohler 12HP Kohler K301 Valves tune up and carburetor also M12″ is in sale since Monday, March 18, 2019. This item is in the category “Home & Garden\Yard, Garden & Outdoor Living\Lawn Mowers, Parts & Accessories\Lawn Mower Parts”. The seller is “bakt4kids” and is located in Wauseon, Ohio. This item can be shipped worldwide.