If I am correct the usual way to fix a Porous head is the drill the offending Oil way slightly larger and put a sleeve in.
I have a couple of questions.
1/ Which oil way(s) need drilling?
2/ What material is the sleeve?
I've been told it can be done by the DIY'er so I'm thinking about it. I can get hold of another head if i stuff it up so I think its worth a go.
Any advice appreciated