I have a 03 f250.It has a bean diesel 6position with 4in exhaust and cold air intake. Nothing big but plenty of power for me. I do a little bit of towing. Nothing more then a 3/4 ton truck. I'm wanting to put a lift on it. Either a 4in and 35s or 6in and 37s but not sure about the power loss. I'm not wanting to regear it so not sure what to go with. I live in West Virginia so I got a lot of hills. All opinions needed!