How is the suspension set up on that? Coils in the front and leaf springs in the back?? You may be able to substitute Dodge 2500 or 3500 drop springs to use on the van. Weight being the biggest issue. You'd pretty much have to find the ones that fit it and support it nicely, then if you wanna go a lil lower, MAYBE cut off .5-1 coil. If it had leafs in the back and the springs are underneat the axle, you can just use drop blocks. But if the springs are on top of the axle, you have to use a flip kit and with most flip kits, you also need to notch the frame. That will take a lil more with the van of course, but it can be done.