tony,
I put that link there just for your info. I do not know if you would see a difference ported or not. Wrenchbender feels it will be fine and he has been doing this stuff for a long time. If you have the resources to drill and tap the base, and feel comfortable doing it, that would be an option. Is there some reason these carburetors don't come with a factory port?
The obvious options are to try it as is, and change it yourself if not satisfied..or send it back and try to get a ported carb.
I did some online research several days ago on the function of vacuum advance. It was interesting, although I am not 100% sure I understand it. What I do know is that using a manifold port at an idle, you will have maximum engine vacuum and that means maximum vacuum
advance.
I think Hot Rod Lincoln mentioned in his post that this condition might not allow the engine to return to its normal idle RPM... as my dear old dad used to say "take my advice and suit yourself".
Stuart
