Spring spacers

[tsm1@domain.elided (Tom Mandera)]

FYI - I discovered the Skyjacker kit had two slighly longer U-bolts for the
passenger rear springs due to the spacer block that's there.. I put the
spacer back, put the bolts on, etc.

What puzzled me is a spacer on the FRONT.  My passenger (diff) perch has a
spacer on it as well.. the previous owner *said* he installed some 3 degree
shims, but this spacer is square (to the eye anyhow).

I re-installed it as is (if it *is* a shim, I don't know if I put it back in
front/back correctly.. d'oh.. *now* I think of it)

Is this spacer supposed to be there or not?  I know the axles have been
swapped into this truck in the past...

-Tom