GU Suspenson Help

Brent,
Mine has 5" springs on the back too, although with the weight I carry all the time, it only sits about 3" above standard height.

I have not done anything to the trailing arms...they are standard. I would imagine that if you have adjustables, you should try shortening the upper arms a little. This should serve to "twist" the axle tube forward at the top and may provide a bit of gap between spring and shocker.
Are you using those huge Tough Dog shockers, re-valved from a prime mover? They are much wider in diameter and clearance is limited. The gap between my Lovells springs and TJM shockers is only about 10mm.
The other thing to check (before mucking around with the adjustment of the trailing arms too) is whether the spring is properly seated ; you might get a few mm movement there too.
Good luck

Did you put adjustable panhard rods in? I don't know if this will fix it but the axle will be dragged across to the right with the suspension lift. My gu has a 3" lift and the R rear spring is closer to the shock than L, though no evidence of contact.

with a 3inch lift you probably dont need adjustable trailing arms however to counter act your problem adjustable pan hard rods would fix this...

Adjustable panhards wont fix the problem, they will just move the ditt left or right.
Upper adjustable trailing arms will fix the problem but will put a severe angle on your uni joints, and will wear them out faster, or make some rude noises.
I had 6" lift in my old shortie, the easiest way to solve it was cut the coil mounts off and weld them around further forward.
a few washers behind the shock will space them out a bit, but you can only go about 5mm with them (not enough thread)

Take it back to who ever fitted it and hand em the keys tell them to fix it.