i have a 65 skylark conv. with the 300 4bbl. engine. it has the 2 speed tranny with the drive shaft that has rubber insulating 1 tube inside the other. i have a vibration around 70 - 80 mph. i have balanced and swithed tire and rim combos around and decided that i believe it is the shaft. has anyone else had issues with these shafts before? thanks.
yes i just twisted one of those out of balance in my 69 skylark.get one out of a chevelle or have one made.i twisted mine pretty good.the rubber is old and rotten.or maybe you have a bad u joint.....good luck