I recently came in possession of a pattern ship from the late 80's. Needless to say, the engine that was used is no longer available. I have been looking at engine dimensions and can find nothing that will fit the mount exactly, and I cannot change the mount since it is permanently installed. Currently, I have a four-stroke mounted in by the two front bolts (don't worry, I'm not flying it like that!). The mounting bracket on the engine does not quite fit the back two holes. I thought about drilling another set of rear holes, but they would have to be drilled so close to the existing holes that I would end up having one big hole that nothing fits in. Any solutions?