The item I am referring to is SuperSprings not just springs. The drop shackle kit is the Belltech 6401 and I am considering removing the block as well. The SuperSprings basically are an add on leaf that only engages when you add weight to the rear. See the below link. They are designed to help you drop very little, if any, in the rear if hauling a trailer etc. I have 6k trailer that when I drop the back I don't want to go negative on my front being higher than the rear. I do have a wdh but I don't want any sag and this further helps sway. My question is for 3 to 3.5 hours of work is $525 reasonable on this type of project. SSA28 | SuperSprings for Ford F-150, Chevrolet|GMC Silverado|Sierra 1500, Nissan NV 1500|2500|3500 https://www.amazon.com/dp/B00715DL8U/ref=cm_sw_r_em_apa_i_4-wjCb0DJPB9G Sent from my SM-N950U using Tapatalk