Hello there this will be my first time posting, new to the group. My colorado swap lm7 5.3 seems to not be making as much power as it should it made 267/258 and 274/278 after the tune with mods like 216/220 5.60 lift cam, k&n intake typhoon ls intake, no cats, efan, ported tb, 3.73s at 5,000 plus altitude everything else in the engine is stock. Is there something robbing HP??? The enigine has only like 50k i was suspecting the typhoon intake becuase ive seen other 5.3s make 290 with just blot ons? If someone can guide me the right way it will be greatly appreciated thanks!
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Being at 5,000ft above sea level and if the DA at the time was worse, there is your 30-40hp loss.

Post the tune file and logs if you can, that could show something too.