Distributor drive gear shot!

[blown motor]

This happened on a friend's 340. The driven gear on the distributor shaft got chewed down to where it wouldn't grab any more. Thus his engine died. How common is this? Someone told him this gear should be changed every 10,000 miles, I've never heard of that before. Will driving style affect it? He gets on it hard often. Looking for your thoughts on this situation. Picture of old gear and new gear.

[blown motor]

@Chryco Psycho

[Bullitt-]

  News to me but Hughes makes this statement
High volume, or high pressure oil pumps are not recommended as they accelerate wear on any cam gear and oil pump drive gear.

   At least this one is not bronze
https://www.hughesengines.com/Index/products.php?browse=category&level0=QS0gU21hbGwgQmxvY2sgIkxBIg==&level1=T2lsaW5nIFN5c3RlbQ==&partid=34486

[Brads70]

I have the same on my 451with a hyd roller cam, and I have changed it out but there was little wear on it. You need to use these bronze gears with steel roller cams, pretty standard, and yes I would change them out at 10,000
How many miles were on the gear Murray?

[blown motor]

About 30,000 Brad.

[Brads70]

About 30,000 Brad.

Well ya... got your moneys worth outta that one then. Check the cam gear, likely ok . I hope.

[blown motor]

I put that thought in his mind. It's all back together now so I hope it was good.

[Chryco Psycho]

You need to run a brass drive gear on a billet roller cam , the iron gears will chew up the cam , needs to be replaced regularly , part of the downside of roller cams .