Depending on yer suspension, you'll probably have to fix yer Dshaft lengths, too. My rear shaft was bottoming out with the truck just sitting there, which will push against yer Tcase, making big problems. Especially bearing failure.
If yer not running dual cases, I think Bud gets $165 for his singlr mount x-member. Not sure if he includes Ubolts or not. i have his first 79-83 xmember, and I think I spent $30 on 4 ubolts.