This is from Ranchhopper:
The best way to line up the
rear axle is when you take the bed off of the truck there will be a mark on the frame where the wood strip ended under the bed frame rail.Take a
measurement from the front of the 105 bed to the center of the wheel well that will be the spot where your
axle will go.I use a carpenters square lay one side on the truck frame and put the other side on the mark where your
axle centers from the
measurement you got from the 105 bed and it will tell you exactly where the center bolt in the springs should be.Do not cut the frame off until your done because after the first spring is hung measure from the end of the frame where the front of the front spring hanger is and mark it on the other side measuring from the
rear of the frame forward to put the spring on the other side in the same spot also do the same for the
rear hanger.One important thing to do if your useing front deuce springs measure the distance between the front and
rear hangers of the springs on the front of your truck so you know where to position the
rear hanger of your donor springs as they should be positioned exactly the same distance apart to maintain a level frame.A little long winded but I hope this helps you.
This thread:
http://www.steelsoldiers.com/showthread.php?t=28991&highlight=rear+axle+measurement&page=5
