Corvette Performance - vibrating problems

anybody else having any kind of problems with vibrating. my c5 vibrates after about 75 mph. its not constant but pulses, if that makes any sense. Ive looked at all the suspension and drivetrain and cant find anything to loose. any ideas?

Check for bent wheels, tires out of round/separating, or simply out of balance. That's what it most likely is.

(mine did the same, turns our RR wheel is bent and all needed a good balance)