I just rebuilt a rear end out o a 99 Z28 and put it in my 94 TA. I drove it about 3 miles and all is quite until deceleration then a terrible low pitch howling. A little history on the rear end. A friend took it out of his Z28 and installed a 9" Ford. It has a TrueTrac carrier and I put all new Timken Bearings, new Motive 4:10 Gears, a Solid Pinion Spacer, LPW Girdle with a Brace Kit. I'm pretty sure the Pinion depth is good and when I did the contact pattern it looked good. Everything was set up using Dial Indicators and Pinion depth gauges. Pinion was set to the proper preload and the nut loctited. I haven't went back into the rear yet but when I put it on my lift and rocked the wheels back and forth there seemed to be excessive play. Also my friend had 4:10 gears in the rear and it was noisy in his car to but it at that time was setup entirely wrong. Help, any would be appreciated.