Whelp, I got impatient and said screw it. Got the bits out and progressively drilled the blockage out. Put her all back together, test started and she fired right up. Won't think anymore about it.
That seems as how my original lower box is. When I put the two new pieces together, there is a very tight fit from compression along with flanges on both sides. I didn't feel too worried about using some sort of glue or sealer as it seems sealed very well including it is very difficult to even try and spin the rubber joint in the lower air box. When you replaced yours, did you seal it with something like a rubber glue?The coupling is supposed to be glued or sealed to the box.