I have a 2001 4wd 250 SD supercab longbed. I am running 285/75/16 tires, and don't want to go any bigger as I only have a 3.73 rear. I want to give it just a minor lift with 4" f 350 blocks in the rear and x code springs in the front (to replace u code springs). I called the parts department at the local dealership, which was only minimally helpful. After telling me that 250's and 350's were built for different purposes, the parts man reluctantly gave me a quote of $96 for a pair of 4" non-tapered blocks. When I asked him for a quote on x-springs, he told me that he had no such listing, only standard duty and heavy duty at $420 a pair. After clarifying that I wanted the springs which came with the snowplow package, he said that there was no way to tell what springs that woud be. I know that heavy duty could mean 4800, 5200 or 6000 lb, which makes me reluctant to order without knowing exactly what I am getting. Does anyone have a Ford part# for the 6000 lb x springs. Dealing with the parts department seemed like digging a ditch with a teaspoon. Based on advice from the forum, I will have the carrier bearing shimmed to compensate for the additional 2" lift in the rear. Also plan to go with new shocks in the front, as well as new center bolts for all four springs and new u-bolts. Anything else that I need to do for this project?