Pipe plugs in inner wall of tappet chamber

[Twincam]

There’s 3/8” square headed pipe plugs in the tappet chambers of some S blocks. Looks like the holes they plug may have been used to support some coolant chamber sand cores during casting.

One of my blocks had some kind of hardened sealant which oozed out of the threads that is very brittle and chipped away with almost no force, kind of like overheated old epoxy. I don’t know if the sealant was factory applied or someone applied it later to try and seal a leak.

I’m considering pulling the plugs and resealing them. They are really in there tight and thinking of using an impact to try and break them free.

Before I get too aggressive, is there any downside to removing and replacing them?