XHD leaf spring

Hello,
I searched the forum with no joy. I am installing a pair of mopar performance XHD rear leaf springs on my 72 Dart with an 8 3/4 rear end. I noticed as I was getting ready to bolt in the rear end, that the leaf springs have a different spacing for the leafs. What I mean is, they are both have five leafs per pack, but one pack has the second from the top leaf extending farther toward the rear shackle by about six inches, is this to offset torque? If so, what side should it go on, drivers or pass? Thanks in advance.

Scot