340 camshaft question, yea another one.

After installing the XE 274 I didn't have any idle control with the mixture screws.
I'd have to measure the hole size as I don't remember but it's .015 of the slot exposed. Yes I am running a pcv. The spark plugs are light tan.
I had FBO recurve the distributor to fit the cam and they recommend to use manifold vacuum. I have a sheet on how it was set up is where I got the numbers from Don.
With the magnum heads it has a 1.6 rocker ratio so the cam has a little more lift, it that makes any difference.
I have decided to replace the converter and freshen up the engine.
Would this be a case where a set of Rhoda's lifters would help?