Power Mac G3 (B & W), G4 Graphite – Power Supply Bracket $5.00 Stamped 805-2178 Power Mac G3 (B & W), G4 Graphite - Power Supply Bracket quantity Add to cart Add to Quote Continue Shopping Categories: M5183 Power Mac G3 Blue & White, M5183 Power Mac G4 Graphite Description Power Supply Bracket and screws. Apple number 922-3766, 805-2178. For Power Mac G3 (Blue & White) and all Power Mac G4 Graphite models – PCI, AGP, Gigabit, Digital.