I recently back halved my 67 cuda. The car goes straight now, and 60 is 1.25. Tire size is 32x14x15. Son is driving and he said car has tire shake about 110-115mph, so he lifted. No shake according to him at all from front end. I have done the obvious, pulled shaft out, shop said u joints were fine and it was perfectly balanced. Had him replace them anyway. Prior to second pass we tightened springs on rear big guns about half an inch. It was obvious after 1st pass the tires were hitting top of wheel tubs as there were lines on both tires in same place, so chassis installer had us change ride height using springs. After he returned from second pass and said it still vibrated, I loaded up and went home. Tire pressure was 7.5lbs, no changes made there. Son and checked pinion angle and it was down one degree. Installer changed instant center by moving both upper and lower bars up. This change was after multiple calculations by him on bickels program. Change was due to what he called a violent launch. It doesn’t do that now. The one thing I did notice was there are NO weights anywhere on the rims. Aren’t rims supposed to be balanced even with slicks???

I’m not really sure what else to look for, for safety sake I have ordered new (31x1x15) Hoosiers, but they are back ordered everywhere, as many have already stated.


Interested in any opinions,

Thanks,
Bill