Everything except this 68SEC000FU rubbish will run over their rated speed

I'm pretty sure, that freescale actually meant "FU" to mean "%&$#?@!%&$#?@!%&$#?@!%&$#?@! YOU", because these CPUs aren't overclock friendly

And by the way: the CPUs run WAY cooler if you run them with 3.3V.