FWIW I`ve been driving/racing my junk w/as much as 7 degrees nose down w/multi-leafs and never a problem. The drive shaft in my car now is 13+ years old on the same u-joints and no problems and just brought it down to 4-5 nose down w/my rear end mods. 0-on trans and 4-5 down on rear w/Cal-tracs...........