Im going to replace my GX15 in a kyosho alpha 3

Is there any good engines that fit right on, or do i have to drill new holes etc?

I need a .15 engine that is relieble, easy to adjust and doesn´t overheat , do you have any suggestions ? or maybe i should use a .12 ?

Im thinking about GS15R, is it a bad choice ? It is the only one i have found that fits right on

I dont race just driving for fun, so i am not looking for a race engine, horsepower is NOT that inportant, i need an easy, relieble engine.