I'm getting .184 to .193 on the original 9mm 2468 injectors with the old copper sealing ring in the new head. This is a CPL 858. The shop manual doesn't list the spec for the 3.9 engines, only for the 4.5 rear gear train engines so I'm assuming not that critical? Do you guys pay any attention to this? I'll install new sealing washers. Any benefit to trying to even out the protrusion between cylinders by lapping the sealing washers?