I believe my LS is an S80 case as well. Is there a size difference between the S80/Y80 tranny where the diff would go? I know that internally the GSR and LS are different, but the GSR and ITR are the same...as far as the diff size goes.
__________________
2015 Ford Mustang GT Fastback - Ingot Silver - 6M - Performance Package - Gibson Catback, JLT CAI, FR 47lb injectors, BAMA E85 tune, Eibach Sportline, BMR wheel hop kit, UPR oil separator, Steeda shifter bushing/bracket
Team B.O.B.® - Ballaz on a Budget