Distributor recurve

Your measure ments are close enough.Not much advance past 20 degrees,yes thats about right. Short answer use distributer as is except change vaccum advance to the 8.5 one 17 degrees instead of 22. With fast burn rich mixture and vaccum advance Peak combustion pressure occurs much too early, rough runing and ping could result.That 5 degree difference would allow base timing to be increased 5 degrees and timing at low power high vaccum cruise remain the same