Hi Don
In 68' I built a 350 for a short track stock car and also had Carrillo rods, after each season I would rebuild & mag all the parts and re dyno it for the new year
About 3 months into the 5 th season a rod broke and did it in, so the money guy says what the hell happened
Well you raced it for 4 years, hauling around a 3000 lb car on a 3/8 mile paved track with lots of off & on the gas cycles so I think they got their moneys worth
Even Fred's best rods are not going to last forever
Don