I replaced the black spring with a Mr. G. Now, mechanical starts at around 1200 and is all in by 2100-2200. I set my total timing at 36* and it runs great - seems more responsive and no ping. My son and I measured max vaccuum under load (drove around with vacuum hose coming out of the scoop and into the car) so I can check and tweak the vacuum advance as needed for absolute total advance.
