Well, just picked up a new thrust-pin/spring/cam bolt kit for a whopping $7.00. After extensive research in my laaaa-borah-tory....it seems the pin and spring from the rebuild motor, after 165k miles of abuse by the PO, is identical in every measurment to the new kit out of the package. I don't have any way to test the spring's tension, but they both mic out at around .705 in length. The pins are .834 in length and .248 in diameter. So, if you haven't replaced it in your rebuild, it probably is nothing to worry about. However, if you forgot to re-install it......
Maybe someone doing a rebuild on a much higher milage engine will update this one day???