This is a 24-Volt Delco 40MT Starter, Using DE Housing #1969323 (Others), a 12-Tooth Drive (Accurate #4-489), and Lester Armature #2023. The 3955 is a Right Hand Mount (82 Degree Rotation) Unit That Will Also Fit (If Rotated Properly). The 4987 is the Same as the 3370, But With a Solenoid Using "Reversed Terminals". The 3374, 3999, 6237, and 6238 Are 12 Volt Units That Use the Same DE Housing and Drive. John Deere is Selling Their TY6699 to Replace the Other OEM Numbers Listed Here.