Just got an 05 Sierra 5.3 z71, added a 3 in lift w bigger tires, K&N intake...I'm thinking about a new muffler and then a bully dog to increase engince perfomance/economy....Any thoughts on what muffler or anything else? Thx

 

A muffler by itself would be minimal gains at best. Mainly it's done mostly for sound. Long tube headers is where you get the most performance if you want to do exhaust mods. As for a Bully Dog, I'm assuming you mean a canned tune? Again, it's not really worth it. Get a real tune

 

If it were my truck I would start with a trans cooler and a shift kit to keep the trans from pooping..especially lifted.

Get a real tune and longtubes or shortys with gutted cats.
Edit:and maintenance is important also. Fuel filter, transfer case oil trans fluid diff fluids power steering and coolant/tstat is all probably old if the truck is used.

 

Good advice, thanks... I'm going to look into each suggestion shortly...

 

As for the fluids, as soon as I bought the truck I had new coolant, trans fluid diff fluid and power steering fluid, as well as mobil 1 syntheic, all within the past 4k miles...And the Bully Dog tuner as far as my research has taken me is a good way to optimise performance and fuel econ, depending on the settings, as well as monitor the truck... But i'm going to look into long tube hearders as batboy suggested...any other thoughts greatly appreciated.

 

What is your axle ratio and tire size? Most likely, regearing and a custom tune should be first on your list.

 

A Bullydog doesn't optimise anything.... its some safe crappy tune that is minimal in difference over stock. I tune with efilive myself and have seen the canned tunes.... yeah not worth the effort. I know the little display is pretty but get an app on your phone and obd 2 Bluetooth plugin for monitoring.

Not to mention the bully dog won't help you once you have headers and high flow or no cats. Many a vendor does tuning. Or buy the efilive autocal and monitor again. Even Diablos Trinity allows custom tunes and the monitoring if you must buy a handheld.

 

I'm not looking for any really exotic tuning or anything like that done to the truck...it is a daily driver, not anything show worthy... Just looking to make things run better with more towing capabilities and some extra power...after reading reviews of bully dog products i'm a little skeptical.... another tuner i found is the Edge Evolution CTS 85250... costa a few undred more than bully dog, but seems quite a bit better...any one familiar?

 

Like everyone will suggest... Get the Black Bear tune.. Or nelson. You'll see much better performance out of a custom tune compared to a handheld.

I had a Diablo predator tuner... And it didn't do much at all for me. It was mainly only useful for reading trouble codes and changing trans shift points and pressure. That was about it. Of course you could get a custom tune through that, but still not as great as mentioned above. Think of it this way, my Diablo worked on my motor and was very conservative so it ALSO works on any other motor you load it on. So its safe enough for everyone as compared to my custom tune, which wont work well on my buddies truck. Not to mention I got that custom tune cheaper than a handheld..

 

First thing i would do is gears. Ask me how i know, i think the best mod i had was 4.56 gears and 33s.