I've run this cam with stock converters, no issues as you are experiencing. I'd go to initial timing first (I'd guess 14*-20* would be a place to start). Then the idle circuit on the carb.
I cracked the throttle blades in the rear just a little bit put it back on, idled at 650 p, then ran at 500 in D... open up the idle circuits a little bit which brought the idle up some , and now this. Crazy...
