The 742 case has shims for the pinion preload so you can just make sure the pinion is torqued to spec. Like stated above if the noise is not increasing than it is probably not eating itself and you could go crazy attempting to get rid if the noise. Some just make noise.

best of 11.24 at 119 mph 1.60 60’. 68 340 S Barracuda Fastback F.A.S.T [IMG]http://i67.tinypic.com/2mnnnnt.jpg[/IMG]