caberto wrote:
I don't know what the B6 stands for... but the 4600 (blue and yellow) are the Heavy Duty shocks. The 5100 (blue and silver) shocks I believe are not as stiff when empty, but will also fit your truck if lifted between 0" ( yes, 0", meaning stock height lol) to I think 3", maybe 2", can't recall.
I have the 5100's and they are a huge improvement over stock when towing... big bumps are now very well managed and the rig feels very solid through all types of road conditions.
X2!
I have the 5100's for 0" lift and they are great!