piston valve reliefs, how to

Rapid Robert said
360 flat top cast pistons. how do I go about adding valve reliefs. it will be a wild circle track cam so I'm assuming there'll be interference. thank you for your time. RR

TDC, sacrificial valve, cut and sharpen a notch... power drill. Finesse the reliefs w a diegrinder. Ooooor buy the tool or take them in.