rhythmic vibration

The pinion angle was something we looked at early on, and it's correct. Here's what we are thinking...there is some engine vibration, we know that. Both of the center sections I have, need help. The vibration might be a combination of those two factors. The vibration is not so bad that I cannot drive the car and enjoy it. I put over 100 miles on it Saturday. When I put the car up for the winter, I'm going to have the 489 center section rebuilt. It's got 3.23 gears in it now, I'm considering 3.55's. I'm fine with that. My mechanic recommends tearing down the engine to see if I have damaged bearings. I'm not so comfortable with that. I'm tired of throwing big money at this car.