327 serious problem

[RALLY]

Originally Posted by Bruce

Could it be the harmonic balancer has spun on the rubber ?
I had this problem years ago on a L-S6, unbelievable vibration.
Bruce

I mentioned this too. Harmonic balancer could be bad. Never heard of a bad vibration caused by timing. I am sure the timing was set correct when starting engine and then make sure it was correct before driving the car. Same goes with the carb. To me if he got 100 miles on the engine without the bad vibration, then all of the sudden it started and can feel it when sitting in the seat, it could be a drive train issue. Before i would of ever torn the engine back down i would of done some real research on the problems i mentioned. Driveshaft out of balance? bad u-joints? loose flywheel, flex-plate? This is not a hi-perf engine here. Have the crank checked again. Out of balance? Check harmonic balancer. Check complete drive train. Dont over look anything. Its could be an obvious thing. Let us know.