6 litre LS or 400 SBC

Discussion in 'Engine Topic' started by gs462, Feb 15, 2010.

  1. gs462

    gs462 Veteran Member

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    Guys, I have access to a 400 2 bolt main small block ,and also a 6 litre LS based truck block, Both will need rebuilt, I'm pretty sure I know the answer to this but I'd like to hear from the engine builders and those in the know. My car is a 79 z28 4 speed, The stock 350 is ok but Id like around 500 hp and was wondering what the expert opinions are. I would like to keep it carbureted, for now. Which motor would you build? Also with the 6 Litre I would use the coil on plug ignition with the msd box to run it.


    Thanks,
     
    Last edited: Feb 15, 2010
  2. KansasTwister

    KansasTwister Veteran Member Lifetime Gold Member

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    keep carbed? go the old 400 2 bolt main, have the block converted to a 4 bolt. Make sure the bores are in good shape, sometimes the bores on the short rodded 400s have issues. If you were closer id love a cheap 6.0 for one of my builds lol.
     
  3. twozs

    twozs Veteran Member

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    the ls motor needs a ecm as it doesent even have a distridutor. a msd box is not enough i dont think
     
  4. KansasTwister

    KansasTwister Veteran Member Lifetime Gold Member

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    oh ya frogot to mention that twoz's, thanks. Ls motor needs an ECM as it uses coil packs, and also doesnt have a provision for a mechanical fuel pump, as well as needed the motor mount adapter plates (these are the one cheap part of the build lol) and then you would have to buy some brackets for the accesorys as the stock small block ones wont work, and the stock ls air compressior would hit your frame, and an oil pan as the stock ls one hits your subframe as well IIRC.
     
  5. badazz81z28

    badazz81z28 Veteran Member

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    Do a price breakdown comparison and go with what you want.

    The LS motor will run you more money but will have the benfit of fuel injection and technology.


    I would go 400sbc. So you can keep alot of the components you already have.
     
  6. gs462

    gs462 Veteran Member

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  7. gs462

    gs462 Veteran Member

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    Do you guys think the 400 can make as much power as the 6 litre?
     
  8. Air_Adam

    Air_Adam Veteran Member

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    The 400 can make 500hp pretty easily (I have a friend with an '86 TA with a 406 making over 500) but it won't be nearly as street-friendly as the 6.0L LS engine. Most of the LS guys I know are making 500+ crank hp, and with much more streetability than my 4bbl 420-ish hp 350.

    I'd go the 6.0L route, even if it will cost you a little more. You'll be much happier in the end. With the 6.0L, you can just reuse the majority of the factory parts (rotating assembly, heads, etc) and make 500hp without any problem. Good luck doing that with the 400ci.
     
  9. badazz81z28

    badazz81z28 Veteran Member

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    All depends on the combination.
     
  10. tom3

    tom3 Veteran Member

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    For the same money, more power I'd think.
     

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