Posted by David S. on July 18, 2000 at 06:15:36:

In Reply to: Re: Transfer INPUT gear posted by Roel on July 18, 2000 at 02:42:07:

In this context, I expect British means BSW / BSF, British Standard Whitworth / Fine. The spanner sizes refer to the thread diameter, not the nut "diameter".
American means UNF / UNC, Unified National(?) Fine / Coarse. The spanner sizes refer to the Across Flats (AF) measurement of the nut.
Metric spanner sizes use the AF principle.

I wouldn't like to give a cut-off date for when BSW went out of use, and you may well find some BSP (Pipe) threads on fuel pipe nuts, on very 1960 British cars. Spanner sizes for BSP are as BSW, of course.
Some electrical connections, such as main leads on starter motors, may also be BSW / F on older British cars.
I refer to Original Equipment, not what a Previous Owner may have fitted.
I have no practical experience of Series Land Rovers, so cannot say if this applies to them.