vacuum gauge to solve idle issue

When I check online for cfm formula, online they say max rpm (6000) x cid (273) รท 3456 = carb size. Which works out to approx 500 cfm?
If I do swap primary Greg, is #86 the part # ??
I will finish cleaning, reassemble tp stock specs, make adjustments (choke too) and post back.
Thanks guys! Much appreciated.

#86 was the jet size, but follow AJ's advice first.
A couple of jet sizes up or down don't usually cause the problems you are having.