108 wb versus 111 wb leaf springs

I can tell you from personal experience that the leaf springs from a Duster (111" WB) are 1" longer than the leaf springs from a 66 Cuda (108"WB), as I used a set of leaf springs from a 1970 Duster 340 car for my 66 Cuda. The main leaf from the Duster was 1" longer than the main leaf from my original set from the 66, so I had to use the main leaf from the 66 and all the other leaf's from the 340 car to come up with a set of assembled HD springs for my 66. There was no way I was gonna get that Duster main leaf to compress that far without some kind of bind!!! Just sayin', Geof