Idle drop by 500 rpm?

Ironracer said
Timing is @22° according to a Matco dial back, still pulling vacuum in park @1200 rpm.. need to locate a piston stop..seems like she wants more timing. Fires right up, no drag on starter

Now wait a minute. Up there ^^^ you say you have it idling at 650. So which is it? 650 or 1200? Why would you idle it up to 1200 if it'll idle at 650?