This particular kit is meant for a 5.4L V8 Raptor. For 6.2L V8 ProCharger options, give us a call directly at 623-434-5277. As far as max power, the 6.2L and 6R80 regularly handle 675hp 2.9L Whipple Systems without issues, and many folks have taken them beyond with pulleys and headers without issues. The question on the Harley Davidson trucks is their AWD system and transfer case, which could potentially be an issue. Give us a call directly at 623-434-5277 and speak to one of our sales reps so we can get some more info on your truck and how much power you're looking for.