most likely the reason this is done is the same reason the engineers put the two bottom bolts of the timing gear cover INSIDE the engine, no bolt to hold the harmonic balancer, a steering box you have to take half the truck apart to remove, a master cylinder you need to use a funnel or a laser bomb sight to fill, the battery that tries to tear the skin off your knuckles when you go to lower it into the little hole, Little things like that. It doesn't make sense and doesn't need to be that way as can be evidenced by the fact they changed all that. The simple fact is the distributor will probably work fine with nothing but a grease cup, with a felt plug, a bakelite plug, or both. personally I would go with nothing spring loaded rubbing on the shaft if I were rebuilding it, it may not be concours correct but there were MANY things about these old beasts that could stand improvement. however I do have a freshly rebuilt distributor from chev's of the 40's still in the box (actually a ziploc bag) that I really don't know what is inside that part, and I am quite sure I will never know, because it was only $90 and will most likely last as long as I live, or long enough...
