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The number on the distributor will give the total centrifugal advance, and the slope it comes in by rpm, the total vacuum advance, and how it comes in by inches of vacuum, and the general mechanical info such as end play and side play in the bushings.
Your right about 8-12* initial and 32-38* all in at 2500-3500 rpm. But that’s typically US small blocks. Over the years I’ve had several engines where everything from the cam, compression, porting, intake and exhaust manifolds were all modified. Factory specs are just a starting point for a good tuner. I’m not that good, but I’ve know people who are.