My brother has a cheap P.O.S. Murray Riding mower with an 11 HP Tecumseh Enduro engine with a nice window in the side of the block. I've been looking for a short block only to find there is NO short block for this engine(OHV135/206914E). Where can I look to find a cheap briggs 11 or 12 HP electric start that he can just bolt on. (Not real mechanically inclined).Who can cross a Tecumseh over to a Briggs?