When surfacing heads that have had brass tubes installed in head bolt or pushrod holes, I slip snug aluminum plugs in the tube to support them while cutting. This prevents the cutter bit from grabbing the tube and folding inward. This works great on any application where a thin wall repair sleeve is used. The plugs last for many heads as you only take a small amount from them each time.
Ron Flood
Cedar Machine
North Branch, MN
