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1999 chevy suburban 5.7 vortec ~need performance advice

Discussion in 'Performance & Fuel' started by mattewhitesuburban, Feb 2, 2014.

  1. mattewhitesuburban

    mattewhitesuburban New Member

    Hey guys , I'm new and love the great amount of info . OK as for my truck , I am building a project , so I ordered the 6 inch lift and the 35 12.50 tires as well as the black xd rock star 20 inch wheels. I need your guys help here please . So I'm new to the 4 x 4 scene and I am new to the fuel injected builds with all the different vortec engines . I see all the different things that are being done whether internal basic bolt ons ... superchargers and my favorite turbos . I built 9 Sec cars and engines from when I was 15 till now so I Amy pretty knowledgeable. So on to the mods .... I have basic bolt ons ...
    Already installed
    Magnaflow high flow cats
    Magnaflow series 40 2 in 1 out stainless
    All stainless exhaust 3.5 inch single
    Yes single but it does sound great . He ran it higher for the 6 inch lift .
    Royal purple diff
    Royal purple power steering
    Royal purple oil with filter

    it's cold so I haven't installed the items below
    msd vortec cap n rotor
    msd coil
    msd 8.8 plug wires
    Plugs ???? I need
    ok so future

     
  2. Boonduff

    Boonduff Member 3 Years 100 Posts

    Swap the diff gears to 4.56s. The stock 3.42 or 3.73 will have the motor lugging all the time.
     
  3. BurbanMan

    BurbanMan Member 1 Year 500 Posts

    would 4.10 gears not do ok?
     
  4. Boonduff

    Boonduff Member 3 Years 100 Posts

    If you already have the 4.10s in it, go with, but if you're gonna swap I'd go with 4.56s. A suburban is a heavy vehicle and needs all the mechanical advantage the deeper gears will give it.
     
  5. buckmeister2

    buckmeister2 Member 1 Year 100 Posts

    you didn't say what you are trying to do. If you don't mind 10-12 mpg on the highway, the 4.56's will be fine for you. The 4.10's are a good compromise in most cases, but the large tires are going to make them behave like 3.5. It all depends on what you want to achieve...towing power, top speed, off-line acceleration. If you have done all this before, you know you have to have a goal in mind.
     

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