Probably aero…most trucks are like big boxes and it really runs out of breath up top. The flange from the exhaust manifold to the turbo is barely bigger than a quarter so that doesn’t help at all. I think DPs will help out a little, but we will see. Some guys are upgrading turbos but not manifolds, it almost seems senseless to me with a restriction like that.
http://i540.photobucket.com/albums/gg324/LivernoisMotorsports/EcoBoost/DSC_1119copy.jpg
I’ll look into gearing, haven’t really done that yet.