If you were wondering if you could put an IMS Twin Turbo 128 PCI video card from a desktop beige G3 into a PowerMac G4 Quicksilver and use it for a second monitor, say an NEC XV14 running at 800×600, yes you can. (Oh, put it in the top slot if possible.)
I offer this advice to the next person trying to confirm this by searching the web and finding no useful information in that regard.