Which Timing Gear?

[31 Woody]

Probably not a good question as I am only looking at a $90 decision…but, here goes:
I have a rebuilt B engine to install in my Cabriolet. The B block currently has a new fiber gear installed. I am considering pulling that and installing an aluminum one. Backstory though—Several years ago the engine on our Station Wagon decided it wanted ‘love’. As it was getting the attention it needed, a good friend was doing the work and said he was installing an aluminum gear. I initially protested, and he asked “do you like changing timing gears on the side of the road?” Wow, what a great response. Nearly ten years later the wagon is fine, but we have probably only put 3 or 4 thousand miles on it. So now I have another Model A, that won’t get a million miles on it…. The fiber gear will probably last forever based on my usage. But it’s apart already. How many miles/years should someone expect from the fiber gear?

I do realize the crank gear and backlash are something that needs to be considered as well. I do not know if the crank timing gear is new or used, but I do plan to check. Thanks!