a single 3 inch manaflow will more than support what your (and most of us) are doing with these trucks and looks great.
2005 crew cab, new crate lq9 with comp 212/218, 558/563 on 115 cam, 80mm t.b. coated long tubes, off road y, flowmaster cat back, dynomax bullet, ngk plugs, msd wires, k&n cold air kit, 4.10 gears, auburn pro lsd, transgo shift kit, nelson drive tune, trailblazer i-6 torque convertor, anzo lamps, ss front bumper, z71 tahoe rear bumper, debadged, kenwood touchscreen with headrest monitors, JL components, coaxials, sub, 5ch amp. bell tech 2/4 drop. 22x10 ss wheels with 285/35/22 bfgs.