Cylinder head 3/8” plug questions

[AshyLarry]

Hello Oilburners,
Huge fan and very grateful for the knowledge that I have gained from this site. My truck is 1992 f350 7.3 idi n/a
I have my cylinder heads out and I’m trying to clean them up as best that I can at home. My question is there are 4 plugs between the intake and exhaust valve springs with a 3/8” square for a ratchet to loosen them.
My search for a coolant/fuel/air passage diagram for these heads has been unsuccessful. In the pictures I circled the plugs that I’m thinking of taking off.
Any input on how to properly clean the heads will be much appreciated. The amount of sludge under the valve covers, on the rockers and in the valley was an area of concern when taking the top end off. I imagine it was a dirty cdr valve.
I had a leak between the block and head at the rear of the the passenger side of the truck which encouraged me to do the head gaskets.
Name the part it is either broken or has been fixed already. Never imagined becoming such a good diesel mechanic when I bought Ashy Larry but my knowledge and research has hit a road block. Definitely taking the front clip off has made this job a lot easier.
Thanks for the help,
Paul

 

[IDIBRONCO]

I don't know if it's necessary to remove the plugs between the valves. The one(s) on the ends of the heads are oil galley plugs, I think. The big one on the intake side close to the glow plug hole is for a coolant passage and probably isn't necessary to remove either. You may want to have the heads inspected for cracks since the center of the heat tab appears to be missing. It's in the stainless "freeze" plug in the picture that shows the end of the head. IIRC they melt out at about 270*, but I may not be remembering correctly and it may be a lower temperature.