This morning, I read your answer to Lou Lacy in Ask Paul in the Aug. 5 issue concerning his engine vibration.
I have been an FAA CRS certified for dynamic prop balancing since 1991. I would strongly encourage him to investigate and find the problem before he conducts any further flight.
I agree he did not give much information to you. His cited weight correction number of 96 grams on a typical Aztec spinner diameter estimates to over 550 gram-inches imbalance. I would guess the balancing equipment would be indicating a vibration level of greater than 2 inches per second or greater — far above the maximum 1.2 IPS that a balancing technician is allowed to correct.
I would be especially worried if the vibration appeared recently.