Rear drive line noise

[dscowell]

The past 2 years I have been having noise coming from my rear drive line.  It start around the summer 2 years ago and stayed til around December that same year.  The noise finally stopped when my rear u-joint on the axle end of my drive shaft blew up on me, lucky the axle pinion and driveshaft stayed intact.  I replaced the U-joints and I didn't hear the noise  come back until this summer and this time I made sure to replace them before they blew up again.  Once again replacing the joints stopped the noise.

 

This time when the noise came around I made sure to pay closer attention.  It only occurred around the 2500-3000 RPM range no matter the speed, gear or how much throttle I gave the truck.  If the truck is in neutral and I revved it to 2500-3000 RPM I wouldn't hear anything so it only happened while the wheels were turning.  I'm thinking the U-joints aren't just bad because this has happened twice around the same time so it has to be something else right?  This also didn't start happening til I put a C8.25 in the rear.  

 

The best way for me to describe the noise is squeaky.

 

My truck has ~3" lift, C8.25 rear, stock driveshaft and transfer case.  The rear axle was professionally installed so the angle should be correct.

[Incommando]

If the snout length on the 8.25 is different then the d35 your driveshaft may be the wrong length and putting pressure on the joints. Just a possibility

[dscowell]

That was the first thing that came to mind!  Could it possibly be anything else?