Er…that's kind of a recipe for destructibility, not the other thing you say you're looking for. Think about it for a minute. Your distributor has a nylon drive pinion—the kind factory-installed on millions of Slant-6 engines. The distributor locks up for some reason—there are several. That sucks, but all that happens is the engine stops and you need to repair or replace the distributor.
Okeh, now replace that nylon pinion with a metal one, lock up the distributor, and the damage gets quite a lot more extensive and expensive, starting with shredding the camshaft worm and easily spreading to the nearby oil pump, etc.
The nylon pinion, installed correctly, is much more than adequate. If you have some strange fear its durability is inadequate, make a note to change it every three decades whether it needs it or not.
