This spring pack is manufactured by Deaver Sprngs exclusively for us to our specifications and is added in place of the overload leaf on your stock spring packs. It gives you approximately 1.5" of lift on a 2wd or 2.5" of lift on a 4wd. They can be used with rear blocks for added lift (see our block section for our off-set pin blocks). The PRG Deavers greatly decrease axle wrap and drastically improve the ride of your Titan. Typically, longer shocks are required. In our opinion, these springs are mandatory to keep the 2wd Titans from bottoming on harsh trails or even going through big dips in the road. 
Note: there is a 1 year warrantee one the springs but if a leaf cracks, we will only replace that particular leaf and only if the break is "outside" the ubolts. If the break is in between the ubolts, your ubolts are loose and there is no warrantee.