I was having trouble getting the A model timing "just right". My first discovery was that the control rod was too short....and the OEM rod was not adjustable. The fix was easy: use the long throttle rod from an 8N, which is adjustable. I got one, cut it down, re-threaded it & put it on the car. It helped some....but still not right. I'm just not good enough at this mechanic stuff to adjust it by ear, so I figured I'd use a light. So, I made a pointer, found TDC, scribed the pulley, then measured the correct distance for the advance & marked that. It took two very, very small adjustments on the distributor cam to get it dead on w/ the light. Many thanks to JMOR, Jim UT & John Smith for help on this project!