Idle engine knocking, increases with RPM speed?

I have a 92 GMC Sonoma 4.3L V6 and it has a
knocking noise that seems to be coming from the
lifters but I'm not sure. The oil gage doesnt work
even after replacing the sensor. I have replaced
most sensors including knock and idle air control
sensor and it makes it run better and for a few it
takes the knock away but once I rev it up the
knocking will come back. I was told the oil pump,
the timing chain, or my lifters are bad. I have taken
off the covers and adjusted the lifters to the proper
spec as well. It doesnt knock when cold only when
it starts to warm up and be driven.