Straight pipe shouldn't hurt your truck. If you go with bigger pipe(which will help with cooler EGTs) don't go bigger then 4"s as then you'll actually lose more low end power. Contrary to popular belief, bigger isn't always better.

Also don't fall into the a/m intake line either. They do flow more, but they don't flow more at the correct usable range for a stock or tuned 6.0. There are guys with alot more HP/TQ then I have(508/721) that still use stock filters. And trust me, at the level of cost to get over 500 on these babies, the cost of an a/m intake isn't an issue like some people like to think.

As to stacks, they are almost strictly for looks more then anything else. They don't really net you any more benefit then a single exhaust(make sure it's angled to the side as to not coat your trailer with soot) would.

Tuners/chips is something that is a double edged sword. They can help you or they can really hurt you. I would advocate only tuners that can do custom tunes as those are statistically the most reliable and the ones that have the best chance for most efficiency. However, don't do these with a mind to improve mileage, these are power enhancers first and foremost, not mileage ones. Companies try to play that angle, but for your sanity don't get them with a mind towards that other then, if it improves great, if it doesn't that's ok.

There are tons of other stuff that can be said, but the best thing to do right now is to get Mark's spreadsheet(bismic), read that and then come back here with questions.

 

One other thing to remember 6.0L's do not like to idle for long periods. That will kill your engine.

If you find you need to idle for long periods do a High Idle Modification that will save you alot of grief.

Also "short" trips where you do not come up to temp can hurt you too. Take the 30 minute route rather than the 15 minute one.

If you have a question about this (High Idle Mod) or anything you read in the Tech folders or bismic's (Mark's) spreadsheet start a new post/thread about it. The information will flow.

Again welcome.

 

Fuel "quality" will affect mileage as well as fuel filter changes and only use OEM filters. If you have a lot of stop and go on the route you are taking it will kill the MPG a lot. These engine like to get out and run steady. Once in a while take it out on the freeway for 30 minutes to get the crud out of the system. I've found it does help.