69 340 AVS fuel leak

I took the carb off and sent it to PA for a rebuild. It was all hooked up and appeared to be connected properly from what I could tell when I took it off. The new gasket kit (specific to the 4612S carb for a 340/727) contained the thick spacer gasket. This gasket is about 5/16"-3/8" thick, and the kit also supplied TWO thin gaskets; one for above and one for below the spacer gasket. I can only assume it was set up this way originally based on the fact that the carb kit came with all 3 gaskets.
If there is something I can measure for you, please ask.

George