52 degrees on an sbc????? Better recheck that. I would think 8-12 degrees base timing, then all the advance in somewhere around 2800. If you check it with a light that has the advance knob on the back I think you'll discover it's around 32 to 36 degrees total...

Base timing is set with a light with the vacuum unhooked, then reconnect the vacuum and the vacuum advance and the mechanical advance combined will pull around 24 to 26 degrees for a total of 32 to 36 degrees. At 52 degrees of timing as measured with a light, don't think you'd even be able to keep it running, but if it did it wouldn't run for long.......