[Lemield]

I HATE dash rattles!

One thing I've done in the past is to have someone drive the truck and I sit in the passenger seat with an automotive stethoscope and look for the rattle.

I've had good success with this method.

I have found that in these trucks, sometimes the retractable end of the seatbelt will get cocked sideways and will rattle on the bottom part of the door. Kind of sounds like what you've described...also on my K20, the window crank mechanism has some wear (they are original) and they will rattle sometimes. Moving the crank a little usually shuts it up....

Hope you find it!