Hey i need clarification ASAP, it would be much appreciated.

Is the el xr6 air box exactly the same as the AU xr6 air box?

I am about to buy a ss induction big mouth cheap and give him my snorkel and bottom of the box.
Will the bottom of the box screw straight in and line up?
Is there any difference between the ss induction big mouth for EL and AU or are they the same??

thanks in advance

They should be the same, the AU was built upon the specs of the EF/EL.

The airbox is the same, though the lid may different inside. The EF (and maybe EL) had a shaped exit tube inside the lid; but the AU didn't. You should replace the airbox exit with 3 inch PVC pipe with a bellmouth anyway (there is a how-to on this somewhere on this forum). You can go crazy and swap the induction tube (airbox to throttle body) from a BA or Territory (if you have the space).

From memory, one uses four bolts, the other uses three and has the fourth hole plugged - but that doesn't affect the interchangeability.

I have SS Inductions Big Mouth snorkels on both my EF and AU XR6s, and they are identical. The AU kit comes with an aluminium "air scoop" that bolts to the radiator support in front of the snorkel to direct flow upwards from the grille opening to the snorkel. The EF/EL version doesn't have this piece.

The Big Mouth snorkel is a worthwhile upgrade.