Fascinating, so is there a version of factory shorthand for the R like 'Hi Kiryo' ?
- 'Really Hi Kiryo'?
'Rubbish'?
Not to my knowledge. But this stuff wasn't really meant for the use of us civilians. I think its inevitable that - given how many models, and sub-variants of those models, that Nissan was pumping out in the period - that they would soon run out of alphanumeric coding to cover all bases and/or create confusion from clashing letters.
I think its safer to just accept the codes meaning specific things
per series, but with the caveat of production date. So, in the S30 Series, 'H' prefix indicates L24 engine initially and is superseded by 'R' prefix denoting L26 engine, BUT then the 'HLS30' prefixed 'Datsun 280Z' model pops into the lineup and that 'H' prefix suddenly denotes an L28 engine ('Hi Kiryo', remember?).
As an example of how complicated it gets when you try to apply the prefix codes to other series cars, on the 330-series (Cedrics and Glorias) the L26 engine was denoted by an 'H' prefix...