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swapping 454 into 89 Sub

Discussion in 'The Garage' started by amadosworker, Sep 10, 2004.

  1. amadosworker

    amadosworker Newbie

    Sep 9, 2004
    Likes Received:
    Im sure this question has been asked 1000 times before but i am having a hard time finding information on the subject. I have an 89 /forums/images/graemlins/burb.gif 4wd not lifted, 700r4 w/ 350TBI. I found an add in my local newspaper for a 454 w/ computer, harness, TBI and a 4L80e tranny. I was wondering if this would be an easy swap to do? Is this a direct bolt in or do you have to swap little things like radiator, motormounts, stuff like that? I think i have a 203 transfercase, and was also wondering if the 4L80e would bolt onto that? Any input or links to information would be greatly appreciated. Thanx
  2. 84_Chevy_K10

    84_Chevy_K10 Banned

    May 30, 2001
    Likes Received:
    IL, USA
    Your rig has a 241 transfer case with a 27 spline input. A 4L80E requires a computer to operate and is 32 spline output. An input gear swap or a different transfer case will be required for you to use a 4L80E. There isn't a whole lot of info on this swap (tranny) because it's not all that common yet.

    Motor mounts are the same, if you have an 89 Sub with AC and heavy duty cooling you already have a 4 core radiator, if not you have a 3 core which should be upgraded for a 454, but it may not be essential.

    You'll need the accessories from that motor as your current ones are useless for a big block.

    Although the engine swap itself wouldn't be bad, the 454 would quickly destroy your current transmission and axles fairly quickly. The factory would have never built a rig that way (in fact, no straight axle 4x4 except a K30 ever came with a 454).

    I think that you should pass on it. I don't know what your expected use of your truck is, but you stand to gain little, other than torque, and subsequently, broken parts and headaches from a swap like this.

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