Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

swapping motors

Discussion in 'The Garage' started by ryanstrucking, Feb 19, 2006.

  1. ryanstrucking

    ryanstrucking 1/2 ton status GMOTM Winner

    Joined:
    Feb 2, 2003
    Posts:
    182
    Likes Received:
    0
    Location:
    Calgary AB Canada
    Ok. I'll try posting my problem in this form.
    I have a 87 K5 blazer with a 350/700r4/203/205 doubler
    And I just picked up a 87 454 TBI and I want to swap it into my Blazer
    My question is: Will the harness of the 454 plug into the fire wall (back of fuse panel) without any problems?
    The doner motor is out of a 87 3x3 2wd chevy.
    I cant use my harness as I sold it with the motor:doah:

    Does anyone have any links to wiring harness schematics for these trucks?

    Thanks for your input in advance.

    Heres a link to my other post as well.
    http://coloradok5.com/forums/showthread.php?t=164856
     
  2. Russ

    Russ 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    509
    Likes Received:
    0
    Location:
    Summerdale AL
    My application is not exactly the same as yours, but when I put the 454 in my 88 crewcab dually I used the 454 harness that I got with the engine. It originally had a 350 in it and the harness plugged in correctly to the fuse panel and everything works fine. I preferred to use the 454 harness as it had all the correct sensor connectors on it.

    Russ
     
  3. 76zimmer

    76zimmer Flyin Rat Premium Member GMOTM Winner

    Joined:
    Nov 14, 2005
    Posts:
    23,034
    Likes Received:
    1,349
    Location:
    Kzoo, Mi
    I think you will definitely need the 454 computer and harness, to make it all work right. Different fuel requirements, timing etc.
     
  4. eagle mark

    eagle mark 1/2 ton status

    Joined:
    Nov 18, 2004
    Posts:
    3,289
    Likes Received:
    1
    Location:
    North Idaho!
    The harness that was in the 350 truck would have plugged into the 454 motor. Then all you would need is a chip for the ECM. I'm not sure if the 454 harness from the other truck is? Considering the same year truck and both are TBI with 1227747 ECM my guess is yes, it's the same.

    Did you get the ECM with the 454?
     
  5. ryanstrucking

    ryanstrucking 1/2 ton status GMOTM Winner

    Joined:
    Feb 2, 2003
    Posts:
    182
    Likes Received:
    0
    Location:
    Calgary AB Canada
    Yes I have the ecm and the full harness.
    Thanks for all your input guys.
    I will post up some more pics as the truck progresses.
    Cant wait to get at it but work is getting in the way :mad:

    Regards
    Ryan
     
  6. Russ

    Russ 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    509
    Likes Received:
    0
    Location:
    Summerdale AL
    After having just done this, I definitely recommend using the 454 harness. You can make a 350 harness fit on the 454, but the sensors are in different places and a couple of the connectors are different. It looks a lot better and is less of a hassle if you use the harness that came with the engine.

    Russ
     

Share This Page