It did keep the engine from starting.

FYI, the owner of the machine shop that works exclusively on heads, went over everything I had done because he was skeptical about the valves being the problem. Ultimately, a intake side vacuum test with the cams removed showed that the valves were not sealing.

Since you seem curious, the compression test from before showed:
#1 110 PSI
#2 - 5 about 20 PSI
#6 90 PSI.

You didn't say it was 20 PSI.

I believe you said the compression was "not up to specs" and the valves looked fine to the eye.

Yes, 20PSI will keep it from starting.

Next time give us all the info and maybe we can guess better.

__________________
2012 E350
2006 Callaway SC560

I'm so sorry! Geez!!! I had already told you what the problem was. I was posting so that people who have the same issue in the future would have the information they needed. It sounds like I bruised your ego or something. Get over yourself!