[Killer Bee]

jack up the rear axle, set some good stands under frame, and chock the fronts good..

carefully run it off the ground and see what's out of balance.. keep the revs down in case it gets squirrelly..

in the air without weight on the axle, the wobble may be exaggerated and easier to diagnose..

and be mindful to accelerate and brake gently, rotating mass without ground resistance can snap a pinion or axle..

good luck!