I need some help with an issue

If I bought it and it wasn’t going to create an issue I would rather have a hole than epoxy.
An as cast Speedmaster (iirc for what you and others have shown) is not something to be impressed with but you ported the heck out of it, and improved it beyond what most would ever do, its certainly far superior even with a hole. Didn't you flow it with the hole??

Dress it up some more, call it a
“Signal Balance Port” PBR’s “SBP” a selectively placed tuned port, precisely placed so as to equalize the signal the carb sees.....someone will eat it up!! :lol: