https://www.youtube.com/watch?v=91dmTS-UvDc

Here's a better video of what's happening. This is Tig's car by the way.
I can feel mine doing it when it touches down. I don't think it matters what shock you have on it.

CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax