I need a replacement engine for the Z520 mower that dad blew up last summer. The Cub Cadet dealer would not take it in trade, so he gave it to me. What is the best place to get a new small engine? It currently has a Kohler 25 hp Estate series engine. This is a vertical shaft if it makes any difference. The person I talked to last fall said that that engine has been replaced by something newer and better. I do not remember what he said that was. I am sure all dealers will recommend the same engine. Just looking at cost and shipping costs to central Iowa. Probably similar costs from all in the business. I had looked on e-bay and they were quite a bit higher costs than the person I talked to. Also if there is a dealer to stay away from, I would appreciate knowing that!