Car dropped 250 RPM and is now stuttering

It might have been a vacuum leak at the carb but when I sprayed for a leak nothing happened.

I just confirmed my timing readings again:

700 RPM 12 advance
2200 RPM 32 advance
2200 RPM w/vacuum advance 51 advance.

I am still concerned about my vacuum readings. Prior to this I was getting about 10.5-11 for vacuum at 650-700 rpm. The readings are back up there but jumping around a lot more than previous. Im wondering if this is due to the PCV valve that I have added since my last vacuum reading.