Those carbide burrs can be found pretty cheaply on ebay.

I have an air powered die grinder but have actually had pretty good luck just chucking them in the end of an electric drill -- much quieter.

just send it to BEGi and they'll do it for you.

I've ditched my HF $10 die grinder for a $25 Kobalt (Lowes) die grinder. Infinitely nicer. I'm slowly replacing one HF tool at a time...

I use a typical steel bit with an air diegrinder when I port 2560's. I make the hole in the housing almost as big as the flapper hole, maybe 1/16" smaller on the radius. Blend the inlet into the flow as best I can or until I get bored.

Had creep problems with mine.

Sent it to BEGi to get it ported for FREE.

No more problems.