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Carb to TBI question

Discussion in 'The Garage' started by nad, May 6, 2007.

  1. nad

    nad 1/2 ton status

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    A buddy of mine says if I put my current TBI setup on the carburated motor that I'm going to put in my truck, I will need to swap cams too. Is that true?
     
  2. Tire

    Tire Registered Member

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    I don't see why you would have to do that at all. You aren't going to be digging in that far for the install, all top end stuff. Btw what kind of fuel pump are you planning on using?
     
  3. Blue85

    Blue85 Troll Premium Member

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    Well what kind of cam do you have in it now? If it is hot, the TBI will at least need a new chip to run right.
     
  4. nad

    nad 1/2 ton status

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    I just have a stock 305 with TBI on it now, so its all stock internals as far as I know. My buddy is selling me a 350 with a messed up carb on it, and I thought it was just as simple as swapping intake manifolds. But my buddy said I'll have to pull the original cam out of the 305 and put it in the 350 for it to run right. If it's gonna be all that complicated, I'll just buy a new carb for it, or get it rebuilt.
     
  5. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    You will need a TBI friendly cam and also new injectors as the 305 and 350 injectors are different. You will no doubt need a chip for a 350 as well. The timing and fuel curves are different and that's in the chip.
     
  6. nad

    nad 1/2 ton status

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    Yeah, then I guess I would just be better off using a carb on it. Sounds like a lot of work.
     
  7. southernspeed

    southernspeed 1/2 ton status GMOTM Winner

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    As 4x4high says, but also, as far as I'm aware, a TBI manifold won't bolt straight on to an older carbed motor because of the angle of the centre manifold bolts.
     
  8. nad

    nad 1/2 ton status

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    So if I put the motor in and keep it carburated, what exactly do I need to do? Will I need to replace the fuel lines or anything?
     
  9. nad

    nad 1/2 ton status

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    Also, will a 350 turbo tranny bolt up to a NP208? Thanks.
     
  10. southernspeed

    southernspeed 1/2 ton status GMOTM Winner

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    You'll need an FPR. A th350 will bolt up with the right adapter. I'm not sure but I think you may an HEI dizzy rather than the TBI one.
     
  11. nad

    nad 1/2 ton status

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    Well damn, I might as well just go find a TBI motor then, for as much work as it will take to make these things work. I'm doing this all myself, and I have never done a motor swap before in my life. So it will be a learning experience, and hopefully doesn't take too long, and all works correctly when it's done.
     

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