EXAMPLE: K321 is the same as a K321s, K321AQS and so on. If they try and bore your cylinder before they have your new piston, GO to a different machine shop because they do not know what they are doing. Order your NEW piston and take it to the machine shop. The machine shop measures the NEW piston and adds in the tolerances then bores the cylinder according to the piston size. This is how it is done and you have to make sure it is done this way if you want it to be correct and last for years and years to come.They have gone on mowers and pulling tractors all over the world! Instructions on how to properly install your connecting rod. (The oil hole on the rod 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 Quality, cost saving tools and other COMPLETE Engine Rebuild, Refresh Engine Rebuild Kits to rebuild your own engine, so please check out my other auctions for tools, lawn, tractor seats and other rebuild kits. 020 in 10, 12, 14. The item "Fits Kohler Engine REBUILD KIT FOR all K321 std piston withgaskets for 14hp Kohler" is in sale since Thursday, May 19, 2016. 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.