If you're going 2.79 and FIC, you going E85? I'd add in a diff brace and any driveshaft will probably be fine. Ask 20 people, you'll hear all the same manufactures from different people. I heard horror stories of DSS so I went GForce, Wiles were good but some posted on FB having a slew of problems with their last batch. You look, you'll find complaints against them all.