well i still have this issue with the vibes. how can i tell if the driveshaft is centered in the car or is it supposed to be to one side of the car more than the other? i measured from the side of the D/S to the frame on both sides and got a 2" difference, not sure if its supposed to be the same, any ideas? also i tried another driveshaft again with the same results. then i tried another center same results. i tested these with out the axles in the car, so i can eliminate all that, and still has vibes at 35mph but in reverse at the same rpm as forward there are no vibes at all smooth as glass