I have a '85 Sunrader Classic 18' rv. The engine has 129,000 miles. The valves and seals have been replace 2 years ago. It is burning a lot of oil -- a quart every 400-500 miles. The bottom of the engine probably needs to be replaced -- rings, etc. Another option is to replace the engine with a remanufactured engine. Anyone have any experience with rebuilding or replacing the engine? Being told that the 22re is too small to hold the weight load of the rv. Thoughts? Thanks.