IMO, if the cam bearings are ruined that was caused by the cam and not debris. I think the tolerances between bearings and cam is too tight to let anything but the smallest debris in. So, whatever killed the cam bearings did not necessarily kill the rest of the bearings in the motor.
So, the whole bottom end could be reused as long as you are sure it is clean of additonal debris. You may want to disassemble to make sure of this and to do the cleaning.
At that point you would be able to reassemble using new cam bearings and cam. This and gaskets would be the only new parts you would need unless you find additional damage during your tear down.
If the cam is found to be the problem you might get a new one from whoever you bought it. Maybe a gasket set too. So, you would be out a few thousand hours, big deal... :rolleyes:
