Hello all, and thanks for everyone who posts on this forum. I've found much good help and humor here for years now trolling from a distance... but after exhausting the archives for what I could I finally had to make an account and see if I could figure this little problem of mine out. I have a Rochester 2GV divorced choke, large bore 1 & 11/16", large spread bolt pattern close to what I've seen referred to on here as a "rectangle pattern", that came on the car I believe based on the serial (1969 impala 327/t350) with the matching intake. I bought a new carburetor since the Amazon deal seemed right at 90 bucks vs 40 for a rebuild kit and float and the time to rebuild it. Regret the decision a bit now, but since I am down the rabbit hole already here I am... I digress so I'll get to the question. What in the frig is this hole here, maybe EGR?And can I plug them with jb weld and use the new carb and use what appears to be the equivalent vacuum system for what I believe to be an idle enrichment circuit of some sort? I will also attach some photos of the differences between the two carbs. Hoping I can at least Frankenstein the two together and have a well working carb between them. Hopefully this all made enough sense with the photos. .