Differential or Transmission Clunk

[Peckadelic]

If this was a front-wheel drive car, my bet would be on a bad CV joint.
That sounds like noise from the rear suspension, control arm bushing bolt loose, allowing it to rotate.
Does it do it every time when you hit the gas?

Nope, Only from a stop. I believe I have figured it out after reading everything offered here. I think all my slip yokes need lube. There will be play near the torque converter sometimes, then sometimes in the rear, then sometimes both. I'm tempted to rip off the drive shaft and try something, but I also hear the noise eventually comes back.

The noises are directly underneath the cab, lined up with the drivetrain.