First of all, the Sears number for you engine is 143.049001. This crosses to a Tecumseh model HMSK90-XXXXXXX. Can't give you the spec number, as my chart does not go that low. Short block number is 756337D, no long available, but you might find one on the web. Most of the basic parts are available, but will need to be purchased individually. If your mechanic is any good he should be able to find them. If you purchase a replacement engine off the web, 1. it must be an HMSK model, 2. make sure you have pictures of all sides to compare, and then consult with you mechanic and see what he says. He will be doing the conversion.