Nah, when you get right down to it there is no Apple original CPU card that will fit in a Sawtooth period, EXCEPT for the cube cards, the gigabit cards, and some of the slow, single-CPU DA cards (up to 533, maybe 667. The 733 won't fit).
Thing is, of those models, the only one that had a CPU that was enough faster than the Sawtooth to make the upgrade worthwhile is the DA. And while the DA CPU will physically fit in a Sawtooth, it will not work properly in the machine.
The digital audio machines have a 133MHz FSB. The Sawtooth machines have a 100MHz bus. And unlike PCs, practically speaking, the bus is not overclockable. Which means that a 533MHz DA CPU will run at, uh, 400MHz in a Sawtooth. Unless you change the clock multiplier by soldering on the processor module.
And if you thought desoldering an IDE port sounded tedious, you will not want to tackle the kind of soldering you need to do to move the resistors that you need to move around. They're surface mount and very, very small. How small?
See this:
That's on my dual 533 DA card (though the resistors are the same regardless of whether it's a DA, Sawtooth, Gig-E, or QS card). Locations R60, R62, R64, and R66 are populated with resistors to control the bus multiplier. That ruler at the bottom of the pic? It's metric. Those resistors are 2mm long. It took me an entire night to solder 30 gauge wire wrap leads to those 8 pads and 8 more on the top side of the CPU. It's not something you want to tackle if you don't have a lot of experience soldering already.
Which brings us back to the original point: The only practical way for most people to upgrade a Sawtooth processor is to buy a 3rd party upgrade card from Sonnet or Gigadesigns or someone else. =/ The Sawtooth is not the easiest G4 to upgrade the CPU on; the Yikes models were worse, but the DA is much, much better.