GM Truck Club
THE PREMIER CHEVY TRUCK & SUV FORUM
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 9 of 9

Thread: 4.3 to 5L swap?

  1. #1

    Default 4.3 to 5L swap?

    Hi all I have a '99 Silverado with 4.3 litre 6 cylinder with the 5 speed stick, I was wondering how hard is the conversion to a 305 small block v8? Are the engine mounts the same? computers and harnesses? Also, will my transmission be able to handle additional torque of the v8? Thank you.
    Keep It Smooth.
    KE5PVO

  2. #2
    Legend

    Join Date
    Feb 2008
    Location
    Red Wing, Minnesota, United States
    Posts
    3,356

    Default

    the 305 came from a different family of engines for different years of trucks, you would need a 4.8 or 5.3.
    99 K1500 Suburban LT "THE BEAST"
    Hypertech III, K&N, true dual
    285/75/16
    ___________________________
    Jason

  3. #3

    Default

    Will a 4.8 go in you think with minimal modifications? And can the tranny handle the additional torque of the V8? I dont ever plan on abusing my truck but I would like the additional power.
    Keep It Smooth.
    KE5PVO

  4. #4
    Legend

    Join Date
    Feb 2008
    Location
    Red Wing, Minnesota, United States
    Posts
    3,356

    Default

    I would think that in your case its the same tranny for the 4.3 to 4.8, I would do some research though
    99 K1500 Suburban LT "THE BEAST"
    Hypertech III, K&N, true dual
    285/75/16
    ___________________________
    Jason

  5. #5

    Default

    Thanks, i will do some research.
    Keep It Smooth.
    KE5PVO

  6. #6

    Default

    im pretty sure iv read that the 4.3 and 4.8 tranny are the same. but the computer, harrnesses ect are diff not sure about the mounts but research the crap outa this b4 starting.

  7. #7

    Default

    trannys are the same, clutches, and flywheel are different

  8. #8

    Default

    Thank you all so much for the inciteful information that I have been looking into. Most likely ShamRock (she is a green Silverado 1999) will have a V8 come late summer.
    Keep It Smooth.
    KE5PVO

  9. #9
    Sr. Apprentice EKperformance's Avatar
    Join Date
    Oct 2008
    Location
    lake City Florida
    Posts
    45

    Default

    how abouta 5.7, it and the 4.3 share the same harness i think, all the sensors and everything are the same right
    2002 silverado 4.3 5spd / off road y pipe, flowmaster split duals, K&N filter
    ported throttle body , ported heads and intake < all by me

Similar Threads

  1. 5.3 Cam Swap?
    By ajfdirtrider in forum Performance & Fuel
    Replies: 4
    Last Post: 03-12-2010, 11:04 AM
  2. 350 swap
    By lvaubel in forum General Chevy & GM Tech Questions
    Replies: 5
    Last Post: 10-26-2009, 08:55 AM
  3. rear end swap or gear swap
    By rmagni in forum GM Powertrain
    Replies: 4
    Last Post: 08-18-2009, 07:42 PM
  4. Swap 350 for 454...what needs to be done?
    By rzhorne in forum General Chevy & GM Tech Questions
    Replies: 19
    Last Post: 07-15-2009, 02:47 PM
  5. 5.3 swap
    By devilsalmostfree in forum GM Powertrain
    Replies: 0
    Last Post: 01-19-2009, 08:32 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •