Rear end noise Clanking

I have just bought a 66 GT-350 clone. I seem to have a problem with the rear end clanking. The noise only occurs after I have made a sharp turn at low speeds and then continues for about a quarter mile. The clanking is intermitent .I have an auburn posi 355 rear end 8.8. My mechanic is not able to fiqure it out.
please Help with advice.
 
Auburn is a locker setup. It is a great rear end for straight line performance. Once you change the oil and add the posi additive. it will settle down. The clutches in the unit are very sensitive. For example if I am getting on the freeway on a curved on-ramp with the power on and hit a bump............ :worship: .....turn left :nice: