Being that it's a Craftsman you'd be better off just getting a different tractor new or used.

Thanks, what do you recommend? and what's wrong with Craftsman?

Google the model and type numbers from the top of the valve cover and check for a replacement engine. This time of year, you may find a good price on a machine that fits your needs. Compare to the engine price and there you go.

Agree with both previous posters the price of rebuild is costly and time consuming , unless you are well versed , Redundant . A Quality Donor Engine or Tractor would be likely more Cost Effective :) .