Depends on the material you choose and stuff like that cold air intake if you look properly you can get for like 250 and a cat back exhaust I was quoted 220 for aluminized dynomax super turbo but I refuse to go with aluminum it rusts way to fast I'm going stainless steel which costs a little more, and I think I'm going to choose banks Borla or Gibson, don't know well see but all together a guess of roughly 500 but I have a 4.0L, alot of guys here will tell you if your gonna do all that you might as well just regear. Because it brings back alot more of your power, jp mag did a test on the whole regear thing and achieved alot of power back on the dyno instead of the huge lack with bigger tires.