Newer OBS leaf springs vs square body spring differences?

[Stomis]

I couldnt help but notice the 54" tahoe springs I pulled from the junkyard for my trooper are packed a little different than the old 52/56in springs I messed around with from my 87.

Besides them seeming to be of a much better design and built better (maybe its just cause theyre newer) I was curious as to the reason for the steel shims between each leaf in the center of the pack. Also does anyone know why the spring eye on one end is wrapped under and back around and on the other end its wrapped over and back around?

Im sure its the same on 64in chevies and none of it really makes a difference I was just curious.

 

[Fred_M1010]

The steel shims are there to reduce friction between the leafs I think.
I believe I've seen that in a set of old 56" springs as well.

Btw is the center pin centered on the tahoe springs,
or are they offset like the 56" springs?