check everymac.com and you both will see, that
Dual-Processor Mac things do not fit in Dual-Core Mac machines and vice versa.
DP .................... vs. ... DC (to which the Quad belongs, too)
grafic-slot is AGP vs. PCIe
PCI/PCI-X is PCIe
Ram is DDR1 3200 vs. DDR2 4200
Or did you mean Dual core 2GHZ instead of Dual-Processor?
I have a 6800 AGP and 4x 6600 PCIe, which I do not know if they work (cause PowerMac G4 AGP is incompatible. I would send them free for shipping costs, to test. Unfortunately I am in Europe... (shipping would just be 17EUR, but with taxes I guess it is no good).