Rear end clunk turning left

DoctorDiff said
What kind of additive are you running?

The Sta-Lube Equa-Torque brand sold by Napa and AutoZone does not work nicely with fresh, clutch sure-grips.

I recommend Ford Motorsport/Motorcraft or GM/Delco Limited Slip Additive.

Before I ran this CVR or something can't remember. Today I put in redline but didn't get a chance to test because of the bigger problems