I had a 97 1500 4x4 with a 5.2 and 5 spd tranny. I put a Gibson single cat
back exhaust and a K&N filter kit on it at the same time. I noticed an
improvement in top end power, was much easier to pass without downshifting.
Mileage went up a bit too, I was averaging around 21mpg, 22 or a little
better if i was easy on the gas pedal. The Gibson exhaust had a nice deep
mellow tone, wasn't at all obnoxious. I think i paid around $300 - 350 for
it, long time ago, not sure. The K&N filter was pretty cool, it was just the
regular 14" chrome type, just a bottom and a nice lid with a round filter,
looked great, bolted right onto the the plenum. My recommendation, if your
gonna get the air out faster, do something to get more in as well.