What would cause a severe vibration at and above 55 mph on a 91 z24 3.1 with an automatic had tires rebalanced no change car does not pull or drift just shakes like crazy Outer CV's are good?

I had the same problem with my 1990 z24 and finally found that it was my tires had runout. I replaced my shocks and strus and new tires and it resolved my problem.

Answerit is most likely your tires are worn out AnswerHave your shocks and struts checked out and if that's not it then most likely your motor and trans mount are bad. I just had the same problem with my 02 z24 and spent only 100 on new polyurathane motor mount and tranny mount.