There are afew things you have to watch for when doing what you plan. If you get an older style lift where on the bracket for the passanger side brakcet it uses a plate to drop the stock bracket you will have interference with dropped braket hitting the diff. Another difference is that the rear o the rangers are sprung over vs the explorer sprung under. I bet that is where you are seeing your price difference. You are looking at the prices of ranger kits that are using blocks to lift the rear, then comparing it to explorer kits that are using new leafsprings to lift the rear. You might beable to get away with a longer shackle and add a leaf in your stock rear springs to kt it to match the front. Or you could move the springs oon top of the axle in the rear but that will give you more then 4" of lift. Hope all that makes sence