This is NOT a good first soldering project. The process voids your warranty. The Quadra 700 has been successfully accelerated by exchanging its CPU clock oscillator for a higher frequency unit. The original oscillator is a 50 MHz unit from which is derived the 25 MHz and 50 MHz clocks used by the 680RC40 processor. Speeds up to 33 MHz are usually attained with new oscillators.
Higher speeds are attainable by some individual motherboards.
One can reasonably expect to attain 30 MHz. Higher speeds are likely but not guaranteed. There is a small chance that your particular motherboard is incapable of higher speed. Higher speed testing pending. Failed 1 machine failed at 33 MHz.