Quick carb rebuild question

[Jcab256]

Hey guys.. I've been a lurker for about 15 years or so. I recently purchased a 72 GMC camper special the 402. It runs, but not great and I’ve tracked it down to being an issue with the carb. I disassembled it to do a simple rebuild on it, but noticed something potentially concerning. I don’t know if it’s flaw in the casting, or if the casting is broken from someone prying on it previously. On the main body in between the secondaries, there is a hole that goes through the back of the casting. The exit point looks like a break, and not factory. However, this is the first time I’ve ever taken a carb apart. So my question is, does anyone know if this hole is needed, Or if I can be a epoxied closed or..... The first picture shows the hole I'm talking about, and the second picture shows a small wire but I pushed through to illustrate the hole to the outside of the carb

Thanks in advance

[Jcab256]

Hey everyone. You can ignore this post, I was playing with the gasket on the air horn, and realize that once they are mated, it’s blocked off anyway.
Moderators, feel free to delete this post

[brown7373]

That rectangular opening in the back is for a hot idle compensator that some models have. If so equipped, the larger round hole 2/3 down in the rectangle would be open and a spring valve would cover the hole and open when necessary. Then a cover attached at the two holes would cover the opening in the casting. I'm not sure if the Idle Comp was used if it also had the hole in the top you referenced.