Since I heed my own advice, and put my money where my mouth is, so to speak, I ordered two new crab caps for the big dogs this season, because I just don't want any problems associated with caps this season. I figure if it was going to happen, I would be out with a boat load of friends, and it would probably cause a near panic aboard if a motor acted up. Therefore the hundred bucks I just spent for two new caps and rotors is well worth it, because if I was out on the water stranded, I would rip a $100 bill out immediately just to be rid of the problem immediately!
Mallory 221B cap, with the 319 Rotor, for the Mallory YL 502 distributor that came on the 427 marine motor series. Hope it all fits up nicely, I'll give it a close look regarding gasket and rotor-to-underside-of-cap interference.
Many thanks again for the great info you have shared here,
Since "B-O-A-T" stands for "break out another thousand", I consider myself lucky this time.