If you use it, and I have done so, some stuff that might help out is below.
The one given for a 4 inch lift, well its too big (sounds dumb huh) its just too big even for a 4 inch lifted vehicle and this is to do with the bracket itself. The back part is not braced to the front part or anything and so its too flexible, bendy.....
It highlighted some things for me though. Read eyes wide open now. The OEM cast bracket on mine had bubbles of air in it. It broke so 7016 low hydrogen welded and back together again.
I experimented with the red bits and cut the longer tabs off it to almost half the original height, drilled new holes then bolted that to the diff. After this I made a wedge brace bit of metal that fits neatly under the OEM bracket when its bolted back in. This wedge was welded from the top of the front tab to the almost centre of the rear plate leaving room for the nose tab bolt that's provided with the y bracket to fit back in.
I am glad to say that now its firm and sturdy and doesn't move. I have noted that in this configuration the trilink points up slightly with the almost 3 inch lift I have, and this is an additional aid the the rotated spring perch job I did that points the nose of the diff a little more at double cardan joint.
Additional comment, I like 3's, specially when building things. Now with the mod to the bracket I've done I can see 3's in connections all over the place on it. When the force goes backwards it's not just hanging on the nose bolt, its also pulling back on the front tab and putting pressure in the middle of the back plate causing it to push against the diff proper and stiffen up and resist the leverage from the tabs at the rear, very very solid.
With forward motion it does a similar thing in reverse and the back plate pulls on the wedge joined to the front tab.
No matter where I HIT this setup now it all sounds like i'm hitting the diff proper, all nice and connected. Ive found a decent new ball, not oem and not those baked bean can metal things you so often see, including the original oem one in mine. So ill be fitting it after I lengthen the arms on the trilink. 2mm metal plate for this little job, about 20mm to 30mm more and the diff rotation will be complete and spring perches levelled again.
IMHO:
Summing up, if your not going to seriously mod that y bracket thing, then don't bother with it. It lacks engineering. Design another and let us know how you go.
I'm playing with the stuff at the moment and I have a set of heavy duty longer lower suspension arms from a Nissan GU and matching upper adjustables (aftermarket) that I think just might be worth trying. 5mm thick walls on the tubing I might add too, isn't EBAY great?
Have fun.
Oh, almost forgot, if anyone has any ideas on how to get a decent ball joint (hopefully in rubber) for the other end of the trilink, Im all ears. Or possible even better a bush that is horizontal Im also interested. I got some ideas but not yet tried them.
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KJ CRD 2.8L AUTO 2007
BP ULTIMATE
Extra Transmission cooler
2.5 inch full flow muffler.
Fuel Heater Disconnected.
In tank lift pump

Provent

Boost, EGT and Trans temp.
Engine Bay Vents soon.
Transgo Valve body (no resistor)

Hemi TC P04736587AC replaced (original TC P04736582AD in '07 KJ CRD) - Nice -:)

If im not here Im there....