im looking to pick up an intake and exaust for my 03. i have a quadzilla xillarater chip.and i did the thing where you take out the baffles in the intake tube already. do intakes make much of a difference? is there something i can make that is just as good as a 300 dollar intake? im pretty handy. and i am looking for a 4or 5 inch exaust. i like to stomp out the pedal alot around town and make some noise, but i also tow heavy down the highway almost every day. so i want to be able to talk on the phone and talk to passengers while doing about 60mph. does anyone have experience and suggestions. im doing these things more for the lower egt's and power rather than sound. thanks.

 

https://www.dieseltruckresource.com/...d.php?t=216704

This might help you on the exhaust side of things.

Intake all I've done is gut the tube and drop in a K&N filter and some minor jigsaw work on the bottom of the factory box. I basically cut a hole out of the bottom the size of a one gallon paint can. I also did the same thing on my buddies rig and he dyno'd @ 420Hp/1023 Tq, he had the Smarty on level 9 and 8" stacks.

Just my .02

 

You can put in a high flow drop in filter in the existing air box. Do a search here and you will get lots of choices.
Also, modify the stock air box to let in more air. Such as drilling a 1 inch hole in all the squares in the bottom of the box, or making a cold air pick up using 4 inch piping. All this info is available here as well and cost nothing to a few dollars.
To build something new, do a search for "BHAF" or "****** Whistler" intakes.