Yep I used an adjustable stop. It took me a long time to get to a point where I felt that I had the engine on TDC. The piston stop I used was a homemade one because I could not find the one I bought. The stop bolt was coarse thread, so it did not have as fine of an adjustment as I would have liked. So, repeated the setup probably half a dozen times or more until I got to where I had confidence that I had the engine at a TDC. I even did one setup using #6 just to see if it was different by much. I was not focusing much on the mark on the balancer since I thought perhaps the balancer had slipped and was the source of the vibration. When I did finally get to TDC, the balancer mark lined up with 0 on the tab. During the engine build before I put the heads on, I used a stop and a dial indicator to get on TDC pretty accurately. When the balancer was installed then, the mark lined up with 0. So, I think, even though I swapped the balancers the original one that was on the engine is probably fine.

I did run it without the VA and noticed no difference.

Thanks for your thoughts, very helpful.

R/ John