I had the air tube and then made my own intake set up with a heat shield. The prob with the air tube it sucks in hot air as it set right on top of the manifold. Pm if you need any info
I did something similar to this but i found out the ZJ 4.0 has a larger intake tube with the same size on the TB, its about 1/2" larger in diameter. May not make a difference but they're plentiful in the junkyard so why not?