Stuart,
Yep, the 235 in my '54 (which I believe to be original) does have the octane selector with timing marks stamped into the plate. The shop and owner's manual also show the timing marks stamped into the plate.
Your description of using the vacuum advance as a "real convenient handle" is *exactly* what my dad and I did over the weekend!
Sort of switching gears a bit: when using a timing light and the octane selector set in the middle, the BB on the flywheel was just outside (above) the little window next to the starter. Is it correct to say that if the BB is appearing above the timing window that the timing is late/retarded? I know the radiator fan turns in a clockwise fashion if you are looking at it from the front of the truck, which I'm assuming means the flywheel also moves clockwise.
Thanks for your help--these days I have more time to think and read about truck stuff than I actually have time to go out there and work on it!
