Chrysler Repair: noisy lifters, oil sending unit, valve train

Question
this is a 96 chev P.U. not dodge but should apply to either. ROLAND sounds like most of the lifters in the engine started clattering all at once. after 1000 miles since oil change. the oil sending unit is still showing same pressure as always and rises with increased RPM's the oil looks clean for a 129000 mile truck. the truck is never abused. any sugestions would surely be appreciated THANKS    ROBERT

Answer
Hi Robert,
The lifters need a minimum oil pressure of some level to be pumped up enough to close the gap to the valve stem. I would suspect that there is some dirt in the line between the oil pump and the valve train. I would therefor look into the possibility of opening that pathway and try to clean out its lumen. I can't suggest specifically how to do this but that would be a logical approach.
Roland