Any idea why the cam assembly doesn't want to come off the shaft? This is for a 1972 Motorcraft, if that matters. Yes, the circular retaining spring came out. I already disassembled the '67 dizzy, and that had no problems, it lifted right out. On this one, It will rotate fine (within the limits of the advance limiter boot), but it will only go up and down maybe 1/8". Is there a distributor change between '67 and '72 that I'm missing?