Technical Holes in 81a intake?

Hey guys. I was looking at this intake I have from an 81a (1938) trying to figure out if can use it on am 8ba (1949) and noticed these slots between the intake runner openings. In addition there appears to be holes penetrating through the intake. I don't have another to compare it to so what is the purpose? Looks like a vacuum leak to me.

 

Here’s a bump for ya.

 

It looks like it was done to try and balance the runners but there's definitely a vacuum leak. Some high temp rtv will take care of the problem.

 

If you look closely you should see that hole is threaded..

 

That's to pick up vacuum for the distributor. If you don't want them just JB Weld or RTV them closed.

 

The early intakes had two of those one for distributer and one for windshield wiper motor....

 

Ah! That makes sense. Thanks everyone for the replies.