First off, you have to let us know which 316 you have as Deere made two different ones - one from in 1978 only with a Kohler single cylinder 16 hp engine, and one from the mid 80s to 1992 with an Onan twin cylinder 18 hp engine. The frames on these are different as well as the transmission. The Kohler powered 316 used a closed frame in the rear and had a Sunstrand unit, while the Onan 316 had a open frame configuration in the rear, and had a Tecumseh transaxle. You can check ebay, check these classifieds, and check wfm's classifieds. Post want ads on the latter two. You can also check here: Antique Garden Tractors For Sale Classified Ads - Yesterday's Tractor Co.