FWIW, there are basically two types of alternator fitted to 247 and 248 series airheads. /5 machines were fitted with a 180 Watt alternator. Everything later than that was fitted with a different alternator set rated variously between 238 and 280 Watts dependant on model and year. The sets fitted to post/5 bikes are interchangeable. The main visible difference between the two types is that the later type has an extra terminal low left on the alternator cover with an additional wire to the diode board (the 'Y' terminal). It's worth noting that the later set can't be fitted to the /5 engine unless the mount for the stator is machined out. The later stator has a slightly larger diameter than the earlier one.
As far as the diode board goes, the earlier machines were fitted with a board that lacks the 15mm blade that sticks out on the opposite side to the main battery feed (the 'Y' connection). Later boards can be fitted to/5 models without any issues , just leave the 'Y' terminal unconnected (and preferably insulated)... I doubt if you could even buy an early type. If you do find an early one, it should probably not be fitted to a late bike although the only issue will be a lower maximum output.
Voltage regulators (Mechanical or Electronic) can be used with either alternator/diode board set.
Rob