Yes you can. You have 6 rails of 18 amps each, While it will not be "real" 108 amps, it should at least provide 80/90 (it is a Cooler Master in the end) which is enough for 780TI SLI even. If the power supply is not 4/5 years old, then I would reuse it.
Power Supplies, as all electrical components have a certain lifespan. As time passes by, a PSU loses its initial power. Also, the majority of PSU failures is from aging Capacitors. I will not lie to you, I love Cooler Master cases and their CPU coolers, but PSUs is not something Cooler Master is great at. The unit you have is from the more "acceptable" ones. But since it is over 5 years, I strongly suggest a replacement.