I have a 2008/4.6 and have been running the Steeda UDP's since day 1 with no issues. Hard to tell the exact gains since I did multiple upgrades at the same time. I'd install it again given the choice. No charging issues at all. The Steeda UDP is a quality machined piece and recommend. Avoid BBK at all costs as it's a bad design and can cause un-reported (not me but buddy's experience and legally silenced) problems. Get the Steeda UDP over any other brand even though it may cost marginally more...it's the superior UDP. It's been awhile since I installed it but but the Install is straight forward.....you'll need an impact wrench, gear puller, torque wrench, black silicone for crankshaft keyway, locktite and a new Ford crank bolt (don't re-use the old one).