tablet - replace U7600 with L7400?

[swinebird04]

The title pretty much says it. Any thoughts on the feasibility of swapping the 1.2Ghz (533FSB) U7600 for 1.5Ghz (667FSB) L7400? I realize the TDP difference, but figure rmclock can help offset that (and help the battery too). The FSB is set by the CPU, correct? Should that cause problems? This is in a convertible/tablet. Thanks for any input/thoughts.