The composite gears are softer than their corresponding metallic counterpart, Brian. The composite distributor drive gear needs to drive both the distributor and the
oil pump. The distributor takes little to no power to drive, relatively speaking. A stock
oil pump that pumps
oil at only 50 psi or so takes a lot of power to drive and the composite gear becomes the weak link. A high volume / high pressure aftermarket pump would be death on a composite gear. The best solution is a metallic gear that is compatible with the material the camshaft gear is made from.
The silicon bronze gears while sounding like the best choice will rapidly wear when asked to operate in a non race car sort of environment. Even in a race car environment they need to be regularly maintained because they still wear, producing unwanted changes in the engine's ignition timing map.
Ed