Torker 2 vs Performer RPM?

when you bumped up the initial did you readjust your idle mix screws for best lean vacuum at idle?

6" of vacuum... if it will idle at 850 rpm, my guess you have vac leak somewhere. A cam I'd expect to have that vacuum profile would have a hard time idling there.

Have you checked the intake to head sealing surface? Plugged off everything connected to the carb to isolate it?

Maybe the pushrods are a smidge too long. Don't know but it acts funny that's for sure.