Well, since people were either bending the spring eye bracket to make bar sets for the early trucks fit the '98-up I can't imagine why you couldn't do the same thing in reverse to make late brackets fit early spring eye brackets....
Frankly the front bracket wouldn't be all that difficult to make.
I want to make my own bars, basically I'll make a "double bracket" at the back so I can "cage" a heim joint between the two brackets and eliminate the possibility of deflection, and I'll make a broacket that centers the pivot point directly aboe the spring eye bolt so that the bar IS the exact same length as the front half of the spring to eliminate bind in the vertical direction.
I'll make everything out of 1/4" thick steel and make the "bar" out of
sufficiently large stock so I can have 3/4" threads on the front end
And my front end bracket will mount directly to the frame,
not simply the rear lip of the spring bracket.
Of course to mount the front bracket will require removing the front spring
eye bracket from the frame as the bracket will be a big plate that will mount
to the frame and be mounted by the same four 5/8" fine thread bolts
that will replace the four spring bracket rivets.
AD