Adding Power for the V-6

[Bill Hardy]

I have a 2000 Mustang with the 3.8L V-6 and a five speed that I would like to add power to. My local Ford dealer has v-6 mustangs with a Roush Racing package. He tells me that a K&N air filter and Dual exhaust was added to these vehicles which added about 20 h.p.. Has anyone tried doing these two things? And if so, what were your results?
Are there any other minor modifications anyone would recommend?

Thanks!