I have maybe 40-50k on a rebuild. New crank and bearings, new cam and bearings, high pressure oil pump.It had been running great and the oil pressure was good. Oil level was good. After about a 4 mile drive to church it began a tapping that got louder as I pulled in the lot. It was the first convenient place to stop after it began. It's loud and will make the noise from start up. I didn't run it long after that but it did seem to be coming from the lower end on the passenger side. We pulled it back to the house that night and I haven't looked into it any further. I had run over a limb on our dirt road that hit loudly under the truck so I climbed under hoping the tranny vacuum line had gotten disconnected but no such luck. Any suggestions on tracking down the problem without causing more problems in the process? Any help is much appreciated.