Same amount as what? Most people use the front springs out of a full size waggy and weld the perches above the axle.That alone is roughly 5" then depending on where the shackle is mounted and positioned, can really add alot of flex, adjustable shocks work too.

It sounds like the tires are in his fenders or the u-joints bindind in his axleshafts in the video

 

Agreed on the noise identify, although that is a sketch looking setup. Coil definitely has the flex advantage...

 

coils will get more flex. but not by alot. im thinking i wanna do leafs front and back when i go 1 tons...