Anyone ported stock Magnum heads?

AWESOME!! I'm just getting ready to do this myself, practicing on some old head I found in my buddy's barn.

1wild&crazyguy said

Cut the guide down to half of its height, id love to show u numbers before and after that.

Click to expand...

What tool is used to do this? Some sort of bit that can chucked in a drill? Is it the same tool that could be used to cut down the guides to clear keepers/retainers for higher lift applications?