We have been working with ICON and we have come up with a rear shock for the 2005-Current Tacoma "6" Lug rear lifted application shock.
The shock as of now is the standard part # 56503R-Custom
Its our internal Part #...
The shock has been built for a 3"-4" lift and here are the dimensions.
26.8" Extended length
15.9" Compressed length
You still may have to modify your bumps, but at least you now have the option for a good quality direct bolt in replacement shock
for your 05-Currect Tacoma with 3"-4" rear lift.
I might add, no extra charge for the custom dimension per ICON as of this moment.
Just an FYI..
Hope it helps..