Just a little miffed...

Is there a reason you want the manifold vacuum? That engine should idle at 600 and have 15" of vacuum or more. Also - that total timing is retarded for that engine package and I'd wager the sputtering andd "jumpiness" of the idle is due to the vacuum hookup of the advance. The "putt putt" you hear in the pipes is unburnt fuel popping in the exh pipes when you decelerate.