The improvement is still significant. In stock trim, the truck produced 238.8 hp at 5,200 rpm and 270.6 lb-ft at 4,150 rpm. With the Gen-2 FIPK under the hood, this Silverado produced 249 hp at 5,100 rpm (nearly 11 hp more at 100 rpm earlier) and 281.3 lb-ft at 4,100 rpm (that's also 11 lb-ft more torque). What's even more interesting is that it gained it gained more power higher up in the rev range, so our instincts about a bigger gain with more throttle makes sense. A recommended upgrade, we say.