I don’t have allot of experience timing a 235. But I do have allot of experience having problems timing a 235.
I have a 54 car 235 in my 50, 12 volt, pertronix. When I first tried to time it I could not locate the ball.
The manual for my year states to set the octane sensor to "0" and lock it down.
Loosen the distributor collar clamp. and turn distributor until ball lines up with pointer then tighten clamp.
I painted 2 arrows on the flywheel so I could determine which way to turn the distributor.
I had the Vacuum advanced disconnected. I could not find that in the manual but was suggested here in the forum.
...Watch in HD...link... After I timed it to the ball, I set the idle(450rpm for me), Adjusted the Carb mixture screw to max vacuum reading on gauge. Then Advanced the timing. I can’t recall how advanced I am but I don’t have ping or detonation
Hopefully the more experienced bolters will be along with additional tips. Or corrections
Good Luck