I am having the same problem with my 05 rear end and after doing some research found the rebuild kit on Diesel Power Products is over 1k. I found a complete axle out of a low mileage 6.0 for $400
I would recommend **********'s tunes, I've ran ******** as well and after I did my 175/stock sticks it just never ran right. Their customer service was great, revised it a few times to try and get it right. After I switched to ********** it runs fantastic, I am currently running their street...