alternator worries

so, I just bagged my 99 s-10, but when i got it all wired up and took it out for a spin, my electrical system started to die out... lights dimmed, gauges dimmed and eventually stop reading... it was like a dying flashlight battery... so i obviously suspect the alternator is being overdrawn. I have a dual viair 380 setup, and they are each rated at 16 amps max, so that would add 32 amps of draw to my alternator. so should i upgrade to a 200 amp alternator, or is a stock 105 good enough and mine may have just been on its last leg?