Front leaf spring bushing question - outer sleeve question

[CS1972]

No, I did not put the original style front spring eye bushings with metal outer sleeve and as far as I can tell the rear shackle eye bushings from Energy Suspension seem to be just like the original.

What struck me as odd is that ALL the bushings from Energy Suspension for the entire Front leaf springs were "solid", meaning they did not have little “slits” on the inside diameter like the Rear bushings (see pic). Not sure why that is.