changed pre-chambers do I need to Machine heads

[cubby]

will the head gasket make up for a hairs difference with the new pre-chambers

[britannic]

This is from my military engine rebuild manual:

Check each prechamber for proper installation. Prechamber must not be recessed in cylinder head. Prechamber should protrude from surface of cylinder head no more than 0.002 in. (0.05 mm) at any point, Using straightedge and feeler gage, take this measurement at two or more points on each prechamber. If prechamber protrudes too far, tap into place with 1 1/4" socket and light mallet.

[tom.mcinerney]

Civilian Helm manual also says a little protrusion good; mustn't be below head deck surface [probably so gasket forces/seals to precup]. The chambers (and head bores) are intended to be interchangeable. Don't machine precups level.