Nope, the caliper mounting bosses are part of the fork lower.
BTW, I'd say that it's debatable whether or not a Race Tech'd (or similar) non-adjustable Marzocchi fork is going to be better than an off-the-shelf SBK Showa. That just depends on how well the springs, oil, and valving in the SBK fork fit the rider's weight and riding style. Of course, if you're an advanced or track rider, a professionally set-up SBK fork is going to put you way ahead of anything that you can do with the Marzocchi.
The advantage of the SBK forks over the non-adjustable Monster forks is that even without Race Tech (or similar), if you arent too huge or too small, you can at least get the pre-load and damping close to right. For anybody that's over 175 or so and rides even remotely agressively, the damping and springs in the OEM Marzocchis sucks.
Actually, as mentioned above, if you do get the forks right for your weight and style without doing anything with the shock, chances are it'll just amplify any deficiencies with the shock set-up.
--Fillmore