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TBI V8 swap... a few Q's...

Discussion in '1983-2005 S-Series models' started by bowtiepower00, Nov 14, 2003.

  1. bowtiepower00

    bowtiepower00 1/2 ton status

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    TBI V8 swap... a few Q\'s...

    I've been toying with the idea of throwing a V8 into an S10. I'm not concerned with the mounts, exhaust, tranny problems, etc. The truck will be a regular cab 2WD. I would like to start with a TBI injected truck with cruise and A/C and work from there. The motor will be a 350, but I would like to keep the TBI. The trans will most likely be a 700R4, but if I find a T5 truck then I might consider that route. I would like to keep the factory ECM in the truck and basically just swap the PROM and drop in the 350 (complete w/ new throttle body) with a serpentine setup, A/C compressor, etc. Is this doable? I would think that if I replaced a 4.3 it should be pretty straightforward, but what years of the 4.3 were TBI? If I used one of the smaller sixes or a four I know that the transmission bolt pattern would be different, but what about the engine wiring and controls? I would assume that I could reuse the stock ECM with a different PROM, but I'm not sure. What years of the smaller motors were TBI? Anyone have any experience with this? I don't want a dragster, just a quick daily driver with some creature comforts. (a real sleeper)

    Also, I keep reading about you guys finding clean older S10's with bad drivetrains for cheap, hook a brother up...
     
  2. Triaged

    Triaged 1/2 ton status

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    Re: TBI V8 swap... a few Q\'s...

    EFI started in 87 and so did serp. belts. I think most of the wiring will be right for a 350TBI in a truck that had a 2.8 or 4.3 TBI. I don't know for sure if you can run the same computer. s-series.org has alot of good info on the swap.
     
  3. kennyw

    kennyw N9PHW Premium Member

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    Re: TBI V8 swap... a few Q\'s...

    TBI started in '86, serpentine belts started in '87. The computer will have to be changed to run a 350 as will the Throttle body itself. The wiring is basically the same between almost all TBI setups. Getting a truck that is already TBI is definitly the route to go.
     
  4. jac6695

    jac6695 1/2 ton status

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    Re: TBI V8 swap... a few Q\'s...

    To clarify, I believe TBI started on the S trucks and other V-6 applications in 86, fullsize trucks with V-8s in 87.
     
  5. kennyw

    kennyw N9PHW Premium Member

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    Re: TBI V8 swap... a few Q\'s...

    [ QUOTE ]
    To clarify, I believe TBI started on the S trucks and other V-6 applications in 86, fullsize trucks with V-8s in 87.

    [/ QUOTE ]
    It actually started in '85 on the 4 cyl S10's then in '86 started on the 2.8L V6 in S10's. Fullsize started in '87 with all motors.
     
  6. crazy427

    crazy427 1/2 ton status

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    Re: TBI V8 swap... a few Q\'s...

    I tried to do this swap in my 91 s-15 jimmy 4x4. It was a 4.3 tbi origonally. I dropped in a 5.7 and kept all the serpentine accesories. Alot of customization had to be done to kept the 4wheel drive but you dont have to worry about that.What i did find that might trouble you is the v8 and v6 wiring are different.The spark timing control and knock sensor work differently between the 2 engines. when i dropped in the 8cyl i got a v8 throttle body and tbi distributor 2 match. I alo put a v8 prom in the v6 ecm. It ran but it would only idle, as soon as you moved the throttle it would hestiate back fire and stall. So i tried installing a v8 ecm.It would idle but again it would backfire and stall under acceleration. I played with it for about 3 weeks trying to see if i could correct the v6 wiring harness to work with the v8 but had no success.So now a holley and vacuum advance hei now reside under the hood.I did this swap about 2 years ago but if you have any other questions ill see if i can help. /forums/images/graemlins/thumb.gif /forums/images/graemlins/k5.gif
     

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