Hello all
I'm wondering if anyone can help with whether i need to get my crank
nitrocarburised or whether i should try to find a genuine EN40B S crank.

i'm in the process of doing up the engine in my 1969 aussie cooper s.
apparently its a 'late' mk1 S block with a mk2 S engine number (i can't
remember what the difference is). i pulled it apart on the weekend and found
that the crank is a 12G1287, which according to minisport is a non-S
non-heat-treated crank.
Does it matter?  I was told today that a EN40B crank would probably cost me
over A$1000 if I could find one (but i don't want to spend that much).  or
is it worth getting my current crank heat treated? or is the one i've got
likely to be fine?

my cause for concern is that when my brother had minis about 10 years ago,
he bought a (cheap) clubman with a 1380, big cam and (as he discovered) a
snapped crank.  he ended up putting the same cam into a 1275 and snapped the
crank again.  his next attempt was a 1310 GT motor with a heat treated crank
and there were no more problems.
i'm trying to build a fairly fast engine, and i don't want to use parts that
aren't up to the task...

any advice gratefully received

Thanks