How vibration free is your 70-71 240Z?

Looks like I never finished this thread. I replaced the front yoke and took the propeller shaft to a local shop for balancing. It was there opinion that the shop that did the shortening of the prop shaft did not balance it. When I went to install the shaft into the transmission, the "slop" (the amount I could push the yoke radially) was a lot. As an estimate from looking, I'd say I could move the yoke in any direction about .020". So, that is about a mm of movement radially. It might have been a bit more than that.

So, I decided to replace the bushing that is in the tail shaft of the transmission. Looking back on it, I think the bushing developed wear because of the driveshaft being out of balance for the first 500 or so miles I put on the car. I think that the bushing was sacrificial - meaning made of softer material than the yoke. Anyway, after putting the new bushing in (removal and reinstallation of the transmission was required), the new yoke was tight (no discernable movement at all radially). With everything back together, the vibration that caused me to start this thread is gone!