[ember1205]

Originally Posted by dpevans

Agree on the rear diff, but I would wait until around 5k and be sure and put the correct stuff back in, V6 and V8 take different fluid.

High Performance supplement specifically calls out doing it at 1500 miles if you intend to track the car.

Otherwise, you don't need to touch it until 45k (w/ LSD) or 150k (w/o LSD). 5k nets you no better initial break-in assistance and would be WAY ahead of the earliest recommended general maintenance schedule.