These modern 68000s are very good overclockers. Yaqube's record with the Minimig is just over 56Mhz although not all will go that high.
Is there a plexiglass case available?
Actually, the CMOS 68000s are good overclockers, but why Jens is overclocking a 10MHz component to 14MHz is baffling when there are 20MHz parts (and those overclock as high as 32MHz).
Still, a 68000 is not going to perform anywhere near as well as a 68020 or 68030.