You will need to measure your shaft before buying anything. Toro typically uses a 7/16"-20 bolt on all mowers except for BBC models which use an external 5/8"-18 thread. Toro mowers also use a 3/16" straight keyway instead of a woodruff keyway except on the 1-3/16" long shafts which are on old push models made back in the mid 70's and before. This is a listing of all of the engines that we have that have been used by Toro. Not all of these engines will fit all applications.