Driving thru the southern NM desert, cruise to 75 with acouple long wot bursts. I pull into town and as i open the door i hear a very loud whine. Shut it down, prime it and whine is there then goes away, truck on whine is back. Clearly the fuel pump. Let it sit 30 mins restart and whine is gone. Pump has 40k on it and its OEM. I have a 450 mile drive tomorrow thru desert. Am I good to go or is the pump going south? Tank never went below 1/2.

 

Its fine they get a little louder when they get hot, if it is a delco pump it will be fine.

 

How old is your fuel filter? I've seen nearly plugged fuel filters cause the pumps to get noisy.

(If you even have one, I don't remember what year your truck is)

 

+1, this would be my first concern, but if the filter is relatively new, you're probably OK. I've seen (or heard) Delco fuel pumps that sounded like they were on their way out, yet keep on kicking for over 80K+