Holley Tri-power Rebuild Kit Chevy big block Corvette. This kit includes 3 needle and seats, 1 rubber vent, 1 30cc pump, 1 power valve. And all necessary original style gaskets, and clips you need to rebuild and restore your six pack set up. Outboard diaphragms Do NOT come in this kit but are available. Just click here to get to the outboard diaphragms.