hello fellow stang2ers i have a problem with a vibration in a 78. i have a 89 302 in it out of another mustang of mine.i have an 85 model t-5 out of a 5.0 capri my wife and i had in it. i had the original 8'' axels drilled to 5 lug thought that my be the problem so i found a maverick 8'' put it, in same thing, had a new driveshaft made even a new slip yoke on it ,same vibration. i tried a friends t-5 one evening ,same thing you can take the wheels off with the car on jackstands go through the gears still vibrates. i had a 4.11 with mini spool chunk in the rear swapped it out for another identical setup i had in another stang2 i have .same vibration, so i swapped in the original 3.00 with open diff. the vibration is not as harsh but is deffinitly still there you can notice it more in 1-3 gears now and i have noticed that the vibration comes in around 2500 rpm which would make most of you say its in the motor myself included, but with the car on jackstands you can go through the gears up to 5th gear , and peg the speedometer to about 120mph let off the gas quickly take it out of gear and kill the motor, the thing vibrates the whole car till the speedo comes back down to about 45-50 .i dont know what else to do to the thing i have spent over a year trying to solve this problem to no avail its time for some help or im gonna have to park it. any questions or comments would be greatly appreciated! thanks mike d.