I noticed when the car was idling and would surge or if you reved it the Stock volt gauge would jump up alot... Underdrive pulley issue??? Or something wired wrong?
Sorry for all the posts... keep forgetting the little issues from today!
Put a DMM on the battery and note the delta-V (the stock gauge is too flaky to use for diagnostics). As long as it's stable from 1200 RPM on up, you should be ok.