And here are the part numbers/places I got the stuff
4" dia, 3" long PVC Repair Coupling ($3.13 from McCoys)
Napa Gold Air Filter 6637 (58.49 from NAPA...next time Ill order two online as they were cheaper)
Koehler Enterprises Hose Clamps KE-64SS 2.5"-4.5" = ($4.32 from Autozone)
- Gained some neat noises under the hood, couldn't really tell a difference in throttle response, will have to get back later after a few fillups to see if there was any at all mpg gain. I don't see where some people said the 6637 mod was "Too Loud",
It seemed fairly quiet to me. Next is Foil Delete I think so I can try and get it a lil louder.
Walker Big Truck Muffler
Part Number 21470 from Napa [$77.99]
- I like this mod for the money. Lots of gained throttle response...straight through style muffler instead of the junk factory one. Seems like getting up to speed I dont need to give it as much pedal to get to the speed limit off a light or passing. Only time will tell about the mpg as well. The muffler may be a teenie tiny bit louder then stock but not really noticeable. I think it is about perfect for someone wanting to get rid of the stock muffler but not wanting to sound like a drilling rig.
Overall I've been happy with the little amount of money I've spent on performance mods. Hopefully new guys (like myself) wondering what to do to their trucks...will take these experiences into consideration when deciding on making a DIY 6637 or swapping mufflers.