right now, after the truck is warmed up and has been running for half an hour or so, i will stop at a store and do some shopping for a half hour. When I come back to the truck and start it up, the oil pressure is zero and the lifters and valves are clicking away. Only after I rev the engine, the oil pump kicks in. You can hear the chain rattling away until the pump kicks in.
The motor is good, but I agree about replacing the timing chain and oil pump all at once

Tom Tucker