Hot Rods 4 Banger Dual 97s Question

I'm out of my element on this one and need a 4 Banger expert. We have a very nice running A 4-banger built by H&H with all the good stuff running 2 97s on a Thomas intake with Thomas head, M-13 cam grind, big valves, etc. The question is: Should this engine be idling on 1 carb or both? It runs fine down the road, exceptionally fine to be exact but whenever the throttle is closed whether slowing down there is a lot of annoying popping from the exhaust. In this day of drive-bys I don't want to be mistaken for a terrorist. Thanks to all who can enlighten a V8 guy with his first A 4-banger.

 

Ask the guys on the fordbarn.com web site.

 

or ask these guys http://www.jalopyjournal.com/forum/threads/august-2015-banger-meet-august-already.985613/
here on the H.A.M.B.