Okay, I was given a Traxxas Revo with many upgrades to the suspension, however no motor. So I've been reading up on a few engines: Dynamite "Big Red Monster 28 Mach 2, Xiangtat Original RC 1/8 Blue Black SH-28 4.57cc, and Traxxas 3.3 TRX Engine, IPS shaft with Pull Start. Question is will they fit with out changing the motor mount and which one would be the better choice? All come with pull start however I'm set up for Ez start..