I have a 2001 LS ZR2.

I posted pictures in the new member section... New in NC.

The front end has been basically rebuilt... Tie rods, pitman arm, ball joints are tight, torsion bars seem tight.
I can hit bumps with speed and it does not make this noise, but going, lets say under 20mph... there is a annoying thump, or rattle that seems to be right under my feet.

I installed new shocks, steering stabilizer, greased everything well... but its still there.

Any Ideas???

 

Check the hood pivot bolt. Mine made a Knocking (or rattling) sound and all it took was an O-ring insetred behhind the washer to take up the slack and problem solved.

KDN