X 2 with Widetrack here.
Some more info is needed.
I would suspect the rear end gear is pretty low , like 3.56 or 3.73.
Kinda too low for a truly streetable ride with a poncho mill as the poncho mill makes more torque and can handle higher ratios much better.
Way kool that you have a GMC with a pontiac engine in it.
I would love to here more about it.
Fact is stranger than Fiction