Well the transmission is coming back out of my car. I have been fighting a vibration at highway speed in approx 85-95mph range. There has always been a vibration in the 2600-2800 rpm range in the motor. Wouldn't call it a bad vibration. In fact I rode passenger a few days ago and really didn't notice it around town. Just thought it was solid mounts/body mounts. In 1-4th gear it's really not that big a deal. In 5th more harmonics are transferred and it stays in the pocket longer. Orginally I thought it was pinion angle. Until I pushed in the clutch in the pocket and it went away. I was also able to go through that mph range in 4th and beyond with normal vibration.
When I had the engine built it went beyond schedule and they were impossible to reach for a couple months. They were supposed to send the flywheel I paid for. It didn't show and I couldn't wait. After a ton of research and talking with the engine builder. I have a gen vi block with a gen iV crankshaft. I assumed since they used a gen vi block that was the proper flywheel. Turns out you can use a gen iv crank with a adapter for the rear main seal. Keep in mind this is an external balance engine. After some research it appears the weight is in a slightly different place and the imbalance is 33 OZ in the gen iv and 41.7 in the gen v/vi. 8 oz is quite a bit a weight on the end of a crankshaft. I am surprised it only showed up between 2600-2800. I hope I haven't done any damage to my engine.

Would have been nice for them to put something in my paperwork indicating this little fact!!! Oh well....time will tell.
See the difference?