Starter motor question
well a 318 with a 904 in australia uses a 9 tooth 25 mm pinion
OR
a 10 tooth 27 mm pinion that is moved out by 1 MM in the starter snout.
…or the US-type 10-tooth, 33-mm pinion. It depends on production date.
But their 727 with a 360 in front, uses the 35 mm pinion the US knows and loves
33mm.
and they have slants that can't use that starter or the two above
The starters in Australia are:
9-tooth/25mm, made early by Auto-Lite (Prestolite) same as the US '60-'61, then by Bosch Australia
10-tooth/27mm, made by Bosch Australia
10-tooth/33mm, made by Chrysler and Bosch Australia.
There are no others.
South africa picked from the south american and australian parts bins so its a bit more confused
South African cars got the US or the Australian electrics, including starters, depending on model/production date. There was no South American content.
one could say its a bit of a mine field
It isn't, though. None of this has to be guessed at. Carefully examining what's in front of you (instead of just assuming or going "Blargh, it's all so complicated, such a minefield!") is 80 per cent of the job; once that's done you know what you need. From there the hardest thing at this late date is getting good-quality parts.
rule of thumb right hand drive bellhousing 25mm 9 tooth pinion
Nope. There are plenty of RHD Slant-6 and V8 A-bodies with 33mm 10-tooth starters.