Update:

Today I changed the old plugs (AC Delco R45TS) with a new set of NGK UR4's (Gap .045), another member suggested the NGK V's are a much better plug?

Well, the exhaust pop-ing & rough idle appear to be eliminated......at least during idle & revving in Neutral. Appears a fowled plug or plug(s) on the passenger side was the root-cause. I didn't have a chance to actually drive the vehicle because of insurance/car being garage stored during the winter.

Since the plugs were black & fowled - my next step is adjusting the Edelbrock carb to a leaner condition.

Thanks to all who responded!!!!!