Help on moving shackle boxes for rear stretch?

Hello all. Recently working on ton swap XJ on 40s. HP D60 and sterling 10.5

Looking to stay low cog and stretch as much as I can get away with. I have set the stage for this....meaning I know ill need fuel cell and comp cut.

Plated the frame and removed the OEM shackle boxes. The "frame" extends all the way out to the rear bumper. As mocked up here:




Can you guys school me on rear shackle box placement? Got a few questions to fire at ya:

Im assuming I can just make my own shackle boxes and move them back...?
Is it a good idea to mount under the new "frame" as opposed to the side as the OEM? I would assume this would provide more lift. Im starting with XJ 3.5 lift leafs (and whatever shackle I need)
I see some shackle mounts on rear bumpers? Am I just landing the new mount all the way at the rear and wherever the front is, is where it goes?

Any help is greatly appreciated.

I'd keep the mounts on the side of the rail, solely for clearance under the front mount. You could likely just order/fabricate some shackle relocation brackets and weld them on wherever you see fit

Placement will ultimately come down to where you want your tire to land. What are you running for springs? Could be a good time to go with some long leafs (Chevy 63"?) since you're reworking both front and rear mounts.

If it were me I'd plan to have cage pillars come down right on top of the shackle boxes to tie the suspension right into the most rigid part of the vehicle. That might not be feasible if you move them back under/behind the hatch though.

I'd bolt your tires and leafs up to your axle, roll it under the Jeep to see where it needs to be, then start gluing it on.

Thanks for the reply! Will be making the shackle boxes.



For the rear so far I have:

Offroad anonymous U bolt eliminators
3.5 XJ lift leafs (Pro comp)
OBS F350 OEM shock towers (found this idea on the forum)
(Still need shackles)
(No idea on shocks yet)


Im going cheap on the rear, in hopes to eventually move to link rear later on.



No idea what shackle length ill need, but im starting with the 4.5" lift leafs and cutting big time.

**Sorry im starting with 3.5" lift leafs NOT 4.5

If I recall, flipping the stock springs provide around 6" of stretch. Regardless of what leafs you go with, youll prob want to add an antiwrap bar.

A lot of people hang out there leafs off the back bumper, but I've seen a few bent leafs because the shackle got pushed forward while coming hard off an obstacle

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I assumed that if I moved shackle boxes, I wouldn't need the antiwrap bar?


If I have to have one either way, I suppose id just flip these.

I used Ironman 4x4 fab front spring mounts and their srb with Barnes anti wrap axle mounts. Gained 3” from the Ironman mounts and an inch from the Barnes axle mounts. Rubicon express 3.5 springs, bds 1.5” shackles on 40s. Gained 4” wheelbase.