Spring Pack design

[jmbrodsky@domain.elided]

        IH all,
     
        This past weekend I managed to get a set of rear leaves for a 
     3/4T Dodge pickup.  I couldn't manage to get the main leaf so I 
     figured I'd use my old one.  The packs are 12 leaves, with a 2.5" 
     block for the bump stop, the block has a large tab sticking out of 
     the side.  All tolled, just from the pack alone I'll have about a 
     6" lift.  I probably won't go that high, but I am wondering how to 
     decide which leaves go in the setup and which to leave out.  They 
     start at about 8" long and go to 51" (the full length second from 
     the main).  Also alot of spring packs are asymmetrical.  Why and to 
     which side?  The deviation with these appears to be only inches, 
     but I'd guess there's a reason, anyone know?  Should I put the 
     blocks in?  I noticed while I was checking the sway bar yesterday 
     that the bump stops are a solid steel frame on my travelall.  Is 
     this correct?  No wonder I get a hideous pounding when I go through 
     rain ruts and stream beds!  I'm planning to go back to the yard and 
     get the front springs at another time.  It's a pull-your-part yard 
     and all the trucks seem to have their front springs, so I'm not 
     worried about them running away.  Any help on the rears would be 
     beneficial though.
     
        Thanks everyone,
     

     -Joel Brodsky

         '76 IHC Scout II 345/tf727
         '75 IHC Travelall 150 4wd 392/tf727
         '72 Chev Carryall 3dr 4wd 350/th350 sold, but not forgotten.