Dell Optiplex 320 Core 2 Duo e6600 upgrade?

[kenan921]

http://configure.us.dell.com/dellstore/...s&cs=04&kc=6W300&l=en&oc=bpdwdel&s=bsd

I see the e4300 as an option but the e6xxx series is absent. Is this because the motherboard can only support cpu's with an 800mhz bus?

Any help would be greatly appreciated.