Memory- Can I use 667MHz DDR2 SDRAM (PC2-5300)

I have two 512 MB 667MHz DDR2 SDRAM (PC2-5300) memory cards (removed from my Intel iMac 2.16 GHz (late 2006) when I upgraded it's memory. Can I use them in my old Powerbook G3 400 (Pismo)? The Powerbook currently has (2) 256MB memory cards in it. Before peeking inside the P'Book, and possibly plugging them in, I thought I'd ask here first. :o)

I cannot tell from what MacSales.com shows for P'Book, if the above memory
http://eshop.macsales.com/Descriptions/specs/Framework.cfm?page=pbg3500.html&tit le=PowerBook%20G3%20FireWire