It was pretty much common practice to replace the fiber gear with an aluminum one, especially if the engine was expected to see heavy duty use like in a mid-size truck or a performance engine. They're a little noisy, but a lot more durable than a fiber gear.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!