At idle it is smooth but as soon as I raise the rmp's the engine starts to vibrate up to about 3,000 rpm then smooths out. When I replaced my stock D5 converter with a PTC 10" 3,000 stall lockup unit I had to drill one of the holes slightly bigger on the stock fly wheel so the bolt would fit through it to bolt up the converter. Would this be the cause of my vibration ? Thanks, Kyle.