How's yours running? My TB measures nearly 52 MM... One of the reasons I suspect AE is what is causing this lean pop.
It's getting better, Dave helped me get the Main Fuel table dialed in so my BLM is ~127 ave. Now i'm adjusting VE and PE with data logging. Of course mine's an '88 with 7747 and I'm guessing my cam (207/213 @.050, .466/.484 with 1.6 rockers) is milder than yours. Here's where I am so far;

PE-AE bin 06.JPG