Learned today that my son's alternator is bad in his 85 BJ70 with a 3B. I've been looking around for part numbers, but there are quite a few. Does anyone have the right part number? There are quite a few that start with 27020-XXXXX. I will say that I'm not 100% sure if it is a 12V or 24V. It does have two batteries but that doesn't necessarily mean 24V, correct? How would I tell if it is a 24V System? The next question would be are these still available and is there a replacement? Thanks for the help.