My 04 VLX (Monsoon 340) has a 70amp alternator
I believe the 03 Monsoon was rated at 330hp, 04 - 340hp.
Yes, 03 has a sack for the center where-as 04 has a hard tank.
I've heard of some late model 03's having the center hard tank. or maybe it's the other way around, the early 04s have the bag.