As some of you might remeber from
an earlier post that my 1970 barracuda had a vibration problem when traveling at 60+mph to the point that the car would shake violently enough to make the hood move around and touch each side of the fenders, and the car has good pins.

here is what has been done on the car:
slant 6 car converted to v-8 kmember and big block torsion bars.
440 engine anto trans. Good set of kyb shocks for street driving and converted to late model b-body discs.
Steering box was leaking so I converted early to a FF2 box and pitman arm. Took car out for it's first run and noticed it steered better, still had the vibration. Had old tires rebalaned to see it it help, no diffrence. Bought new Cooper cobra for the front, still no change.
So members said since the tierods were a little loose that thouse could be the culprit. Used the PST larger tierode and solid sleves. Still no change.
Reinspect frontend and decide that is worn enough that a full rebuild will need to be done eventually, so the decision was made to do it now. Tore frontend apart and inspected the k-member, no cracks. Reassembled frontend with new brake rotors, beating, pads, pst polygraphite kit, Magnum Force adjustable control arms and same kyb shocks as they were still in very firm condition. Took car down to a shop for a fun fronend alignment and adjusments. The guy had 30+ years experience with frontend and was using the latest Hunter allignment equipment. Even had one of the guys over from Magnum Force to check all the specs on the frontend while it was being alligned, everything was fine. Take the car out for a test run and it gets to about 5mph higher and the same dang problem is there! also put in new motorounts and tranny mounts.

ok, so now we are sure the problem was in the frontend, even check column and floors for vibration, which were being transfered through to them. Decided to check the rearend out. We jacked up the rearend and blocked the front tires. Ran the motor up to 60-65mph and there was no vibration coming from the front. The rear tires seem to be going out of round in about 1/2 inch and look suspect. Apon further inspection, the driveshaft seems to back out of the tranmission tailshaft at can see about 1/3 of shinny metal at high rpm's.

Since the rear tires are old and suspect those could be part of the problem, going to install new tires today. Now if that does not help, will have to address the rearend itself and driveshaft and possibly a cracked wheel Mind you, I've had 4 mechanics and 2 friends in the car, and nobody seems to guess what the problem is. Any thoughts on the problem?