Great learning thread 69 Cuda, (for me anyway)
I always loved the early 340 TQ's. We always had a problem with the resin center warping on us, common or not I don't know.
The single most biggest issue is using a thick gasket I between the carb and intake. The factory use a very thick gasket. Often this is tossed aside in favor for the 1/16 paper gasket. This is not good to use for any Carter (& Edelbrock carb.)
The aluminum heats up & cools very quickly. I do not know how fast the center resign body expands and contracts, but the rate is different and IMO, probably leading to its violent end due to the stress of it all.
The Carter/Edelbrock AFB & AVS (and if your lucky enough to have a WCFB) will suffer from fuel perculation pretty easy when the engine runs a bit warm and has a thin gasket. Edelbrock sells a thicker gasket for the square bore carbs. Edelbrock *I believe* has gaskets for the Quadra Jet that are thick BUT may not fit or trim to fit. Off hand, I know of no one making a thick gasket for the TQ. If you know, post it up please!