Mainly spinning 1 tire...

And I'll add, if it is between a $300 SG, and a $500 Truetrac, I'll spend $500 because it sounds like the SG is good, but the Truetrac is more than $200 better. What little I've read so far, it sounds like the Truetrac is mechanically superior and is a true maintenance free diff. And as inexperienced as I am, I am a perfectionist. So when it comes to whether I do this diff, or I let someone else do it ... I will do it. It may take me a couple months to do the install once I get it. But it will be right. I've heard a few stories of having a brand new diff get put in and it going bad in short order. So I trust no one.