i have 05 z71 4x4 gmc 5.3 totally stock. Anyone have any ideas on what i should mod first? and where to best place to buy? sorry if this question been asked a million times but the search button leading me no wheres. IS THERE ANY FREE Mods? This is my very first truck btw yeah, so i have no idea what where to start to mod on a four wheel drive truck. Im looking mostly to get better gas millage and power second.

 

ok, so the first question you need to ask yourself is how far do you want to go with the truck. Look at mine, it's the same truck you have...want to go that far...farther?

free mods: airbox mod is the one that comes to mind.
gas milage mods include better flowing muffler and airfilter.
Look in the stickys at the top of this section

 

A custom tune should be at the top of your list for better power and gas mileage, as well as better shifts and a smoother running truck.Where ya at in Louisiana?

 

breaux bridge, Louisiana

 

I would start out with getting it tuned and an exhaust

 

could i replace my stock muffler with a straight pipe for now? this wont affect the cats because of back pressure?... I want to to do a tune up change the spark plugs, which brand should i go wit? and how u do the free airbox mod?

 

anyone?

 

how many miles are on the truck?

 

I think a straight pipe would work just fine. I don't know what kind of sound it would make though.

 

Tune, headers, exhaust, cia