Kyosho Engine question

[Kot]

I have a Kyosho Alpha 3GP with a GX-15 engine in it. about 5-6 years ago something went wrong
(from natural use, not like i crashed it or anything), and I assume its something with the engine since all
the parts are still functioning and can move freely as a rolling chassis without the engine. I put it away
ever since, and only decided to check on it again since summer's approaching (putting stuff on my 'to-buy' list).

What engines are there with three screw mounts on the bottom? Its in the shape of a triangle :P.
Are all kyosho engines mounted the same? also, would i have to change the pinion from the current
engine to the new one, or are they all the same?

I dont want to have to go to the point where i'll be chopping and screwing
the chassis to custom fit a new engine unless it calls for it.