Hi Jose
the CPU is a XC68060 50C, OC at 100 Mhz. . . nothing more.
With those E41J mask, SDRAM and a water-cooling system, the Atari CT60 can go at 100 Mhz.
A couple of years ago, i've read somewhere of a 2060 CPU card, clocked at 100 Mhz. (the CPU is on the market from 1999)
Ciao