Just do the AC. You need the voltage for MSD. They still use this ac cut out on some of the new cars at wot. Dont think its a power thing more like the crappy compressors wont take the sustained rpm at wot cause the 134 has leaked and the low charge doesnt move enough oil.
my buddy heard of this while at UTI, old school trick for dropping the alternator out, it wall be done to my car, not sure when I'll get to it though