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Thread: changing motors

  1. #1

    Default changing motors

    We have 2 trucks that we would like to switch motors in. Will a 1999 5.3 Chevy Silvarado hook up without computer/electrical or other issues into a 2005 4.8 Chevy Silvarado? The 99 is pretty much worn out but the motor is very good while the 2005 is in good shape but we are losing oil pressure so would like to switch them if possible. The 5.3 also gets much better gas mileage! What issues would we run into while doing this? Thanks in advance for any help! Peace Connie

  2. #2


    I believe that they are essentially the same motor on the outside. So, it should drop right in. Problems that you will run into are that the pre 2003 had an egr valve, the newer trucks do not. Also the in 2003 GM switched to drive by wire. So there is no cable going directly to the throttle body on your 2005 and on your 99 there is. If you switch the harness from your 1999 to your 2005 and the pcm it will remedy alot of the issues, but the drive by wire might be the hardest to overcome. you might be able to switch the throttle body from the 2005 to the 1999 5.3L and take care of the drive by wire issue. But, I don't know for sure. I am sure I missed something. someone else will come along to help.

    1995 Silverado 4x4
    6" BDS Suspension Lift-3" Body Lift-Add A Leaf in rear -Trailmaster SSV Shocks-Duel Steering Stabilizer Kit -AirAid Cold air intake-
    4.56 Gears with Detroit Auburn Locker-Pro-Comp Traction Bars with duel shocks-Aluminum Skid Plate Kit-38.5" x 16.5" Mickey Thompson Baja Claws-Constant Dropping fuel gauge

    2005 Yukon XL Jet Power Programmer, Bilstein Shocks, Bilstein rear springs, Helwig Anti-sway bars, EGR Window Visors, EGR Hood Shield, Denali Headlights, Headlight harness upgrade, GE NightHawk Bulbs, White Night Rear lighting system, Russell Braided SS brake lines, PowerStop Brake pads, PowerStop cross drilled and Slotted Rotors,
    2002 Silverado ext cab 2wd (Sold)
    2003 Yukon XL (Totaled)

  3. #3


    Thank you so much for the info.. It was very helpful. Does anyone else have something to add before we get ourselves into a real pickle trying to switch motors?

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