Hello all. Recently lost power in my 1975 johnson 135hp. Pulled head and found a blown head gasket and a cylinder that had a piece of the top ring break and bounce around. Parts are on order and Im looking for a replacement port side cylinder head. Problem is I cant find an exact match and cannot find a interchange listing. Any help, info, insight would be greatly appreciated. Trying to get back on the lake fishing with my two sons. Thanks in advance, Bret. My head has a casting number of 319942.