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2003 gmc sierra performance mods?

Discussion in 'Performance & Fuel' started by jeffz0rz, Aug 29, 2009.

  1. jeffz0rz

    jeffz0rz Member

    have a z71 x cab sierra. 5.3. i pull a 23 foot toy hauler just about every other weekend. i'm looking for a little more umph out of her. she only has 70 thousand miles on her, and i just replaced the ORIGINAL tires about a month ago. this truck was garaged all the time, and when it was drivin, hardly ever, it was all freeway miles. has a average bolt on flowmaster that was on there when i got it. and thats it. after she gets a full tune up, i'm wondering what i can do to help pull that trailer a little easier? intake, programmer, cam, gears? i dont want to go crazy because i love how she drives as is, but more pulling power is a must. any help in this department would be appricated. thanks
    jeff
  2. 99'HEARTBEAT

    99'HEARTBEAT Epic Member Staff Member 5+ Years ROTM Winner 1000 Posts Platinum Contributor

    The list is endless on Performance mods you could Add,Next to the Exhaust you could go with CAI,Headers L.T.,and Tune either Hadheld or Custom.Depending on how much you are wanting or looking to spends.You could go With a Cam,Tubro etc....:glasses:

    BTW,Welcome to the site.
  3. 2ToNe04

    2ToNe04 Epic Member 5+ Years 1000 Posts


    x2 heartbeat

    Custom tune will get the best out of it.
  4. jeffz0rz

    jeffz0rz Member

    i'm thinking my tranny might be holding me back as well. starting to slip, and shift funny. and thats without pulling a trailer. are these transmissions known to have problems ?
  5. 99'HEARTBEAT

    99'HEARTBEAT Epic Member Staff Member 5+ Years ROTM Winner 1000 Posts Platinum Contributor

    Have you checked the Fluid??,It should be pink in color.
  6. jeffz0rz

    jeffz0rz Member

    tomorrow taking the truck in to get the tranny fixed. after she is all fixed up, i want to start throwming some performance parts on her. i'm guessing i should do all the mechanical mods, prior to a custom tune ? id like to do a cam, intake manifold, possibly some heads down the line, might i change the gearing? i'm doing all this for towing pretty much. just want to tow my trailers a litter easier.
  7. sgui

    sgui Member

    wow 70 thousand on orige equip you are a very good driver. one thing to remember the 5.3 is pretty dependable when you start juicing her she gets cranky imho! but let me tell you she can scream sounds to me like you need errr want more grunt with the hauler me i would chip her then if more is needed stuff some gearing in her
  8. jeffz0rz

    jeffz0rz Member

    well tranny is fine. turns out it was my fuel filter that was causing trouble. throwing everything out of wack i guess. she runs and shifts fine now. so, should i start with the basics as far as power adders ? is an intake system really any good, or is a drop in filter just as good ? tb spacers ? injectors ? programmer? exhaust? id like to leave my headers alone if possible, unless they are really choking down the exhaust. i dont know. soo many questions so little time......

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