I am in the same boat. Engine all apart & stories about blowing plugs dancing in
my head.

I am not going to do nothing.

I am not going to drill and tap for brass plugs.

I am going to clean the areas around the plugs as best I can and then apply
Loctite 290 (or equiv) to the outsides of the plugs. On the type 4 engines there
are allot of these plugs around. only a few are accessible with the engine
installed. None of mine appear to have been leaking. But this 290 stuff will
seep into the joint between the plug and hole (if there is one) and seal/lock it
up.

While plugs have been know to blow out I do not feel it is justified to pull all
the plugs considering the harm that can be done. Also, the high oil pressure
necessary to blow a plug may have been caused by a stuck oil pressure valve. I
have checked mine.

I hope I don't eat these words someday by the side of the road, at night, puddle
of oil under the van, kids screaming, wife glaring an evil eye at me.