I started it up on the ground with the driveline back in and sure enough, the driveline sound is gone... I was going to take a quick spin around the block, but gun shy when I noticed the oil pressure gauge. To be honest, I've been so focused on the motor, Fitech settings etc, I didn't notice this before. It sure seems it is falling right when the surge happens. Thoughts??
That could be the oil pump pressure relief valve opening and closing which would calm down with some heat in the oil.
Pull the oil filter and cut it open for inspection, if you have a bearing isuue you will find it in the filter media.