mustangsneverdie

did you look at the axle to see if you could tell anything there

94mustang94

they seem to be fine and i know the wheel bearings are good the tires have no play in them

Lunatic50

Is it a high frequency vibration? To the point that you hear it? Or is it a shimmy?

At what speed does the vibration come in to notice?

Lunatic50

Edit: accidental double post

Jfsram

I know you said you swapped driveshafts but it still might be the driveshaft.
After drag racing gear swaps it's pretty common for driveshaft balancing to become an issue. In fact, it was probably there before but now that you are spinning it at sometimes twice the speed. Balance has to be better than perfect.

94mustang94

the driveshaft came out of a car that has 373s in it just like mine with no vibration problems at all and the vibration comes in around 50mph