67 cruiser stuff isn't really worth much unfortunatly. The birfields up front are coarse spline and pretty weak as far as yota axles go. The rear pinion is also a bit of a weak spot. It's also a coarse spline. What is your project and how much hp are you going to be running? The axles themselves are pretty beefy. If you are buildin a rod and plan on some launches from the stoplights I would look into weather or not you can put later model r&p with a fine spline pinion and also build a good traction bar to keep the rear end from rotating at all. That is usually the cause of the broken pinions.