my car is still getting vibrations at higher speeds and progessivley gets worse. its a 65 with a new t-5 tranny and i just put in a new differential. its wierd, it will stop vibrating if i take my foot off the gas while its in gear, but if i take it out of gear, it vibrates even worse. the only thing i can think of is the driveshaft, but i had it balanced when i put the new tranny in.
(yes, the u-joints look fine)
(yes, the u-joints look fine)