Lights dimming and brightening

I do have an MSD ingnition in there now and I did put a hidden stereo system in. Other than that, all electrical is stock.

Any sources / part#'s for the solid state regulator.

Will a larger capacity alternator be the same physical size as the existing one ( I imagine it just has more wire wraps inside no?)

How would I test for the capacity of the exisintg alternator?


Sorry but I am electrically challenged. Thanks for all you help!