Tractor uses a "4D" battery as standard equipment. The ID info should be on the bell housing, left side, on a machined surface on top, above the 2 side bolt holes. IIRC, there are 3 sets of numbers. 1st set should have a letter C followed by I think 6 numbers. This is the serial number. 2nd set is the model number. Think it will be something like this: D1014C. 3rd set is the "unit number" or production build date, 3C15B, would be March 15, 1983, B shift. There also was an iD sticker under the opening portion of the hood.