In case anyone is still interested, 6400/6500 macs will NOT USE SDRAM. Don't even try. 6400/6500s use 5-volt 168-pin FPM DIMMs but they will also run 5-Volt buffered EDO DIMMs and those are more easily found today (2005) than the FPM DIMMs.
However from what I understand, the 6400 and...