just pulled the head of my 371 are they welch plugs that sit in the top of the block deck blocking some water jackets i have never seen this before can someone give me some info on it

 

If you refer to the plugs at each lower corner they are restrictors, no need to remove them for any reason except deck surfacing. If they are rotted out you can replace with a deep expansion plug, drill a hole in center, a distant second best option. Tough to make them stay put once disturbed, identical replacements not available.

 

thanks coldwar for the info yeah i can see the two restrictor plugs at each end of the deck but in between the first and second bores there are two simaler plugs on the bottom of the deck and one on the top the same goes between 3 and4 i just wonder should i replace them or will the head gasket blocking the holes off do the job