Thank you DannyP, DANNYP, 30WEST, ALAN MERKLIN and ANTHONY on your input.
I'll have to look for this tube connection sticking out of my EMPI HPMX manifold (most likely it would be plugged- don't remember seeing anything like this when I had removed the top end to change out the air mixture jet. I'll talk with Chris at Air Cooled Only up in Prescott.