Revving 4000 rpms on the highway

I knew I have limited slip before, the two black lines behind me told me :rofl:. I was actually told its a Detroit locker since the rear end was rebuilt. I actually had a Detroit locker on my old 80 Volare Roadrunner aswell, when it was new the tires would chirp when turning. It managed to break in a bit and worked well right up until I sold the car.
A Detroit Locker should be a bit noisy in operation as the dog clutches engage and disengage.