There have been some problems and possible related accidents in regards to accuracy of fuel gauges in the older B2' and BA's. They had a float type fuel senseing sytem that would stick when it wore and got old. I believe there was a SB or an AD out on it. All the new A/C have a capacitance system and you can buy the kit for 11k to replace the old one.
The B3 sucks alot more gas than a b2, and the b2 more than the ba. Noticeably so.
RB