aluminum timing gear recommendation

[Werner]

Originally Posted by updraught

Anyone know why Antique Engine Rebuilding would not use a metal gear?

This is because the risk involved in installing a plastic gear is significantly lower. With a metal-on-metal setup, much tighter tolerances are required. If the flank clearance is too tight, you will experience rapid wear; if it is too loose, you may hear a slight clicking soound.
Therefore, as a precautionary measure, the crankshaft gear should also be replaced whenever a metal camshaft gear is installed.
The plastic gear is more forgiving of errors because it runs more smoothly.
When I had to replace the Novotex gear in my engine six years ago—because it was severely worn—I opted for an aluminum gear instead. It was available in a slightly oversized version, designed to compensate for the clearance in a used crankshaft gear.

During the engine overhaul earlier this year, I reused that same gear. It worked out well; I don't detect any bothersome noises.
Meanwhile I think, that was a bit of luck, too.

However, if I had to make the choice again today, I would go back to using a Novotex gear. That way, you eliminate the risk that the gear pairing won't be optimal. And for a classic car, the shorter service life is of no consequence.