So how bad do you think my rear end is?

[ChevyKiller]

Why on earth are you even considering running the stiff diff with your set-up and power? Warranty or not, your rear end is not up to par for what you need and to support your mods and you will be dealing with this issue over and over again (even on the street) until you properly support your mods.

Making a gazillion HP means absolutely squat if you can't do anything with it other than make a pretty dyno sheet. Traction, suspension, and the rear end are just as important (if not more so) than making HP.

 

[GrnBullitt08]

As other have noted, some dealerships are mod friendly. My friend has had the diff in his Whipple Bullitt rebuilt 3 times under warranty and his car runs 11.20's. I had a new 3650 put in my car under warranty and it makes 569whp. The dealership told me I was probably due for new clutch packs and they told me to bring it in.

Jeff (Jeffs FRC) just had his rear and warrantly after bending the driveshaft and the pinion gear.....with the Paxton still under the hood.

 

[FlyByNight]

On a tech side, anybody have any idea on how bad it is based on my description? Are we talking most like about a new LS or more?

May just need some limited slip additive, although after burning up three clutches the odds seem to be against you....

 

[GrnBullitt08]

May just need some limited slip additive, although after burning up three clutches the odds seem to be against you....

The carrier needs to be changed....like mentioned previously in the threads if its binding while turning then the spider gears are no good or damaged, and the clutch packs are toasted most likely as well....

Do yourself a favor and grab lostsouls setup to get yourself running and to have a spare. Take out the current rear end and build...moser axles, better differential ect....then swap lostsouls stock setup for the built rear, at your power levels you need stronger components out back.