Clunk noise over bumps

[TXSUT]

Whenever I run over a bump, such as a speed bump in a parking lot, at any speed over a snail's pace, I get a pretty loud "clunk" as the front suspension rebounds (extends after having compressed from the bump). I have my torsion bars cranked to level the truck, so could this noise be coming from the shocks, as they run out of extension travel?

Thanks,

Pete