checking cam lobe taper/nitriding lobes

As for how how long it might take to show signs of failure.
I built a 340 for my 340 4sp Dart Sport using a Hughes .513
hi energy cam . Breakin seemed to go well . Drove it around for a few weeks before driving from Boise to BIR in Minnesota to race it . On the way home in the middle of Montana it started losing the cam….