I thought this had been sorted, that the big case J-SS.35 was a full 35 size motor. However, looking through my files I find I have p.23 of the 4/63 MAN, Chinn's test of this motor.
Quote :-
It is in the first place, of slightly smaller displacement than the well-known Johnson J-CS (Combat Special), J-BB and J-RC engines, (all .3585 (continued on page 84)....
The "Continued" bit is crossed out by hand, so it may be a typical magazine typo, and not p.84. However, the continuation should answer the question once and for all, - is the big case SS a 35 or a 33? Anyone got the magazine to check?