Thnak you to everyone for all the suggestions.

Flatlander John - At your earlier suggestion I drilled several small holes in a the mast base to give the teflon chip something to bite into. This hasn't worked for me with this boat. I've also tried setting the chip to the front so that it is in the center after I step the mast. It can be dead centered when I start, but it always manages to work it's way back. You may have drilled holes in the 1980 H16 I got from you John, but the 79 I bought definately didn't have any holes and the chip always stayed put. While it doesn't really solve the mystery of why this boat has this problem and my previous boats did not, I'm going to try ordering one of the delrin bearings (#1130).

I bought a delrin bearing once before and really stupidly didn't understand why it had the nub on the bottom, so instead of drilling into the mast base casting I cut off the nub from the delrin chip. I remember the nub being a pretty considerable protrusion.

Does anyone know??? - when you drill the hole to seat the molded delrin bearing, the hole doesn't need to be deep enough to actually go through the mast step base casting and into the front cross bar does it? I obviously don't want to make any hole in the front crossbar.

Tri x troll- Thank you for the jib halyard tension link - some useful info.