Finally got my 78 on the road, and it's running and driving good so far, however at highway speeds, I've got a vibration, it's not in the steering, the car goes dead nuts down the road and the steering wheel is smooth as can be. The vibration builds up then dies comlpetely and restarts, approximately every 2-3 seconds. The car also vibrates when launching from a dead stop, while cornering, almost as if it's being held back, but corners fine at speed. It did sit for at least a year probably a year and a half or more before I got it on the road. Any suggestions? Me and some friends were thinking tires, maybe even u-joints are all dried up? I also know for a fact that the pulley system in the engine bay is off cuz it has mismatched parts after previous owner removed the ac unit. could it be thrown so much to vibrate the whole car? Any input or ideas would be so helpful, thanks guys!

 

Did you check engine and trans mounts ?

 

I just had a lot of repairs done underneath it and i'm pretty sure he went over the undercarriage, but I'll check it out, thanks.