It's too small for that. Pencil lead or smaller. It's located in the throttle body right above the the nut that attaches the carb to the manifold. I do have an actual stemmed port on that side too but it has no vacuum at any throttle position. I suspect the gasket may have that closed off but I've never checked. I'll have the carb off again so I will look. It's curious to me why it would be non-functioning. The only other port is the one I use for distributor advance. It is on the same side and up by the float bowl and has vacuum all the time.
Thanks for your response.
