Nothing to worry about, it's a direct swap, BUT, I am of the school of thought that buggies should have .21s and truggies/monsterst he 'bigger' blocks. The thing is the buggy is so light you might find the Axial a bit too much. If I was you, I'd keep the axial in the monster and consider a better .21 when the Hyper wears out. The Hyper .21 8 port is a highly underrated motor. With a decent low end pipe, you can get good torque from them and they rev to the moon. You mya find yourself disappointed by the top end from the Axial, but I haven't used that motor, so I can't be sure. Just my 2c. In any case, yeh, you should be able to swap 'em straight out. Give it a try, won't cost you anything.