i am pretty sure that all 535's have the 3.25 diff. that is what i have, and it IS a LS. i am currently looking for a 3.73LS and that is what you should have in your car. we would need to swap rear diff. covers and output shafts. it would be a straight up swap. where are you located? let me know if you are interested and then we can talk more -Artie