changed pre-chambers do I need to Machine heads

[cubby]

will the head gasket make up for a hairs difference in replaced 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.

[cubby]

thanx Britannic

[5.7L oldsdiesel]

The prechambers have got to be flush or forget it....i've had my share of troubles with prechambers before....on the 6.2 and on my 5.7 diesel.I had to replace six in my olds diesel because alot of them were cracked beyond the fire ring.....i had to get six used chambers reinstalled and the heads machined to fix the problem.....no problems since then...... smile.gif