Check/clean all electrical grounds to block, battery, and body
Reluctor gap set to.008" with non-magnetic feeler gauge?
Does the distributor shaft have excessive sideways wobble?
Use a voltmeter to check voltage to coil + when idling, with the - lead of the meter to battery -; typically will be in the 6-9 volt range running
Remove the coil high voltage lead from distributor and place near a metal surface; crank engine and see that spark jumps at least 1/4" in open air. Repeat test with a single lead off of one of the spark plugs when idling.
Intake tract:
What PN/type PCV is in there?
Check throttle cable and return to see if it returns the primary throttle to a consistent spot.
Check throttle blade stops on both primary and seconday to make sure the throttle blades are not come to rest against the side of the bores
Put on a vacuum gague to the intake manifold and take readings when runnign good and bad