what is this shake
second, when i get on it or when i get about 2500 rpm in third i feel a shake come on under normal driving. when i get on it, it shakes again from 3rd gear till i get off of it, even as im slowing down. im thinking this is a unbalanced driveshaft. how can i tell if it is.
car has a custom reverse split cam, built 4l65e, and 4k stall if that makes a difference.

