Ditch the "big" and just go with the little "k"
Get creative with it. Swiss-cheese any-thing that you can (not including the frame). take a hole saw to the inner fender suport, shields, skidplates, brackets etc... With a "hole" lotta' work you might take out 10 lbs of useless sheet metal.
Does th A.C. work? If not- get rid of that too. 40 lbs worth of cold air.
Racing seats, problbly will shed 30 lbs total
Chromolly cage, maybe 100 lbs lighter than the normal cage.
Tube bumpers, knock off 10 lbs per end
Ditch the hitch, 40 lbs
Gut the under-dash junk, get rid of the heater doors and dash vents, block off the defoster door so it blows 50/50 (windshield/floor) so it'll pass a safty, no mo' tunes- 10 lbs
Plexieglass windshield, I've seen it done and "look" factory, 10 lbs
2 or 3 core radiators, better yet, go for the aluminum radiators and shed another 20 lbs off the front.
Make it de-delux, get rid of the chrome trim and "fluffy" stuff.
Still, a bare-bones K-5 will weigh in at around 4000 lbs, even the Bummers.
<font color=blue>Twiz</font color=blue>