[quote:171xxxk8][i:171xxxk8]Originally posted by John Schwiebert[/i:171xxxk8]
IXA is the Hercules engine model. The 3 indicates it has 3 timing gears. These engines were also made as a 5 gear engine, however they were not used by Cletrac. If your engine has that tag your crawler is a very early HG not an OC-3 although they pretty well look alike. The HG was made from 1939 until early 1951. Three models of the engines were used. IXA was used at the start. Then the IXK engines were used. They have a 1/8 inch larger bore then in early 1950 they went another 1/8 inch increase in the bore to the IXB engine. Your craler is actually a Cletrac and was built before Oliver owned the company. At least three styles of serial number tags were used from the start of the model to the end of production. Most of them were located on the right (sitting on the seat) frame rail although some were attached to the bell housing. In your case the serial number will be a digit, two letters and then three more numbers. An example would be: 3GA 340. Also look behind the mag as the date the block was cast by Hercules will be cast into the block at that location. Hope this helps. Questions? [/quote:171xxxk8]