Edmunds-intake, hole between carbs
 

Hello, I began to wonder, why there's a plugged hole between carbs? Seems that it's made by the factory, but what was their original idea on this?

Where does this go and can I use it for PCV, if opened a bit

Re: Edmunds-intake, hole between carbs
 

Someone probably needed a vacuum source for something.
And it would still most likely still serve the same purpose.

Re: Edmunds-intake, hole between carbs
 

I would think that the port could be enlarged to accommodate a thread in PCV. If you used the port for that purpose you would need to block-off the pan breather, usually lower left front if you engine has one and use the air filter type of oil fill cap.
Fresh air would be drawn into the engine via the breather cap, then mixed with the blow by from the crankcase and drawn into the intake portion of the engine to be burnt off.
This would be similar to the '64 292 Y block PCV system. The 292's had an angle plug screwed into the intake manifold, then the hose from the PVC would have to be plumbed into the block/crankcase. On a 292 the PCV went into the valley cover to the rear of the carb. You could drill and tape a hole in the front of the intake that would access the block in lieu of the intake chamber, that would complete the fresh air loop within the engine.
I am planning on doing something like the above on my 59 AB engine when I freshen the engine up in a few months.

Re: Edmunds-intake, hole between carbs
 

Thanks! I think this hole is factory made, because it is quite popular in other Edmunds manifolds that I googled.

Some even have the same small pipe attached.

Re: Edmunds-intake, hole between carbs
 

I have the same thing on a Navarro "Universal" dual manifold. It has to be the vacuum port for the windshield wipers, because at least on mine, there is no other place to hook them up. If there is no other vacuum port on yours, that has to be what it was for, as Edmund's main market when these were new, was improving the performance on the "Average Joe"'s car; not racers or hot rodders.

I will agree however, that is not a particularly attractive location.