i tried asking this in another thread but had no results. i once read on here that you could determine which rods you have by the engine serial number and/or engine build date which is located on driver side valve cover. i know nothing is for guaranteed execpt for crawling under the truck and taking a peak in the inspection hole yourself. but i don't own a tool that size which would allow me to remove plug and see for myself. so just for sh---s and giggles, does anyone have the info for this particular method?