1986 Chevy Caprice 305 smblock with EGR

I have an 86' Chevy Caprice v.8 305. When I pulled out the stock intake I noticed underneath on one of the crossovers that the rear drivers side cross has been blocked off completely. It's welded shut with like some sort of metal. Also the HEAD with the same port, the last one, rear drivers side, has also been blocked off with some substance but not metal. I know that these are coolant ports too so my question is do I have to weld shut the port on the new intake? Is this going to cause overheating issues? I actually read other forums that said they noticed this but this was on a newer car like a 2007 dodge or something? Is this a coolant flow thing? PLus my car is overheating now is why i'm wondering. I put it on and cleared the hole on the head without blocking the new intake off. Thanks for the help