I've seen this done, believe was in an old 12 Port News, a guy had installed a pointer through the timing gear cover and notched the balancer. I'll attempt to post this if I can locate the article. Also you could make one similar to the common small block one that attaches to the timing cover.
Just adjusted my valves and had to use a rachet with long extension on the balancer retaining bolt to get motor turned over and line up mark on flywheel. This is probably the best selling point for switching to a solenoid starter.
