Casey in regards to the moving the rear axle back a little this is a little I found on DJM's website, I'm posting just a fraction of what they say because it's just to darn long. Lets see what our fellow Bolter's have to say...."When you place your axle on top of the leaf springs there are two very important things to consider. No. 1 you must move the rear axle back towards the rear of the truck, away from the transmission, around ¾ of an inch. This is done because your drive shaft actually becomes longer when you “flip” your axle. Say what? Gets longer, how? You’ll notice the splined slip joint in the front of your drive shaft. It’s there to allow the drive shaft to move towards and away from the transmission as the suspension cycles up and down. If you were to support your truck by placing jack stands under the frame (both sides) in the rear. Then, with a floor jack supporting the rear end, remove the lower shock bolts and let the rear end down with the floor jack and look at the splined slip joint, you will see a fully extended slip joint. Now slowly jack the rear end up with the floor jack and watch the slip joint contract. If you could jack the rear end up to the point where it was level with the transmission the splines might completely disappear and the drive shaft would be forced into the transmission. This is not a good thing and why you need to move the axle back away from the transmission when you install a “flip kit”. Now the second consideration when installing a “flip kit” is pinion angle. The typical drop you can expect from a flip kit is in the 5” to 8” range, depending on the thickness of your leaf spring pack. And while the rear of a pick up truck is designed to operate in a wide range of ride heights (empty to overloaded) it is still necessary to establish an optimal static pinion angle. Axle locating brackets in most flip kits have a built in angle, by having unequal length legs in the “U”. This works pretty good most of the time, but not all trucks are created equal and often you need to adjust the pinion to get rid of a pesky vibration."................JOSH
