A short recap: I was told by the PO that when this rebuilt '59 235 was installed 30 years ago it had no oil pressure so they never used the truck(51 3100).After I got everything put back together and cleaned up I ran it and had no oil pressure problems.At the very first the lifters(hyd)were noisy but they quieted right down after awhile.The 0-30 gauge reads high on the 30 most of the time. I recently installed a bypass oil filter and changed the oil for the second time in 200 miles. The lifters are making noise again. They rap for a few minutes at startup after sitting for a few hours. Gradually the rapping smooths out and finally disappears.I drive the truck all day with no rapping. Two days ago I decided on a fairly long trip down some winding country roads. I came to some pretty steep hills and while climbing a particularly long steep grade the motor started to skip and lose power. I downshifted but the motor finally died. I managed to roll the truck off the road a bit to a fairly level spot.When I tried to start it up again it wouldn't run.After resting a bit I tried again and it fired but the rapping was scary so I shut it down. After a half hour I tried again and it ran better and finally stopped rapping so I drove it home. When it was rapping bad the pressure reading was low.Now everything is back to how it was before attempting the hills. Starts with light rapping then smooths out. Pressure readings are good.
I ordered a gasket for the pan and I'm going to start inspecting the pump. I've read a few posts here on the subject and will be looking at the drive on the distributor,the pickup screen and anything that looks unusual.
I'd appreciate any thoughts to help me figure out what is wrong.---Jack

1951 3100
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