Runs fine, goes like a train, but on backing off the throttle i get alot of popping and banging in the exhaust.
i do have a small leak from my joiner between the manifold and silencer but what concerns me is that im starting to hear popping from the carbs too.

im running twin 40 dcoes with megajolt and a vernier pulley the timing seems spot on, fuel pressure is regulated via a filer king to 3 psi

ideas?

Popping on overun is usually caused by a weak mixture - in your case almost certainly caused or added to by the leak in your exhaust link pipe. I would sort that first, and see if you still have an issue. Have you tried the exhaust sealing paste? It works wonders!

I can't help on the carbs, but someone more worldly will be along to help I'm sure!

The exhaust paste solution I agree with, you need to eliminate problems 1 at a time.
Fueling is all gues work unless you rolling road it.
You may with luck eliminate under fueling but may bore wash, you'll never know

I would say the exhaust popping is your leak and what ignition timing do you have in the off throttle position as I guess to little timing would cause the carbs to spit back

On another note a wide band Afr gauge is a brilliant price of kit to have for setting up the carbs I spent weeks tweaking and playing getting nowhere got the aem Afr gauge and I had it bang on in an hour or two

Exhaust - had the same problem and exhaust paste cured it.

Ditch