400 big block build thoughts

Engine, Trans & Driveline

  1. mcv

    mcv Member

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    Hey y'all, I can buy a 400 block already bored 30 0ver ready to build.I can also buy a set of kb240 pistons dirt cheap. So how much horsepower can I get with:
    400 bored 30 over
    kb240 pistons
    eddy e street heads 75cc heads (should get 10-1 compression)
    383 steel crank
    290ish duration/ 560ish lift cam
    hooker super comp headers 1 7/8 ...maybe bigger will have to look
    msd dist, msd ignition box and coil.
    eddy tm6 intake/ worked 750 dp... or weiand tunnel ram 2 600dp's.

    I dont want to stroke this one, Iam just looking for something to throw into a mini tubbed, ladder bar car for some cheap fun... since i already have most of the parts. Thanks
     
  2. Jeremiah

    Jeremiah Well-Known Member

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    425-475 crank hp, maybe 375-400whp depending on several factors like ring seal, exhaust, valve job, induction etc. The stock rods might be the weak point aside from the pistons. I would keep it below 6500rpm.

    It sounds like it should rip for an old school combo.
     
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    • Jeremiah

      Jeremiah Well-Known Member

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      My whp number assumes a 727 trans and 10" street strip converter. High end numbers are 2" headers and the t-ram fwiw.
       
    • PRHeads

      PRHeads Well-Known Member

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      If it’s really 10:1, should easily get over 500 with a decent cam.

      That’s only 1.25hp/ci
       
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      • mcv

        mcv Member

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        That's close to what I was thinking.. trans is 727, reverse manual valvebody, and a 3500 stall. I was told by kB tech line I should safely be able to spray a 100hp shot of nitrous. So this could be a fun cheap set up.... thanks
         
      • Cranky

        Cranky Henchman #27 Staff Member FBBO Gold Member

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        Just make SURE your ring end gaps are right with those KP pistons! VERY important with those ash trays....and especially so if you are going to put some of the laughing gas to them.
         
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        • Runcharger

          Runcharger Well-Known Member

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          I would put cast pistons in and spray 200HP before I'd use the Hypers.
           
        • mcv

          mcv Member

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          I can get the pistons cheap, that's the main reason for those... Nitrous is something iam just thinking might be a possibility.
           
        • Jeremiah

          Jeremiah Well-Known Member

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          How cheap?
           
        • mcv

          mcv Member

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          Brand new in box with rings and reconditioned rods for 200$
           
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          • PRHeads

            PRHeads Well-Known Member

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            Just make sure the rings gaps are correct, and keep it out of detonation...... should be fine.

            I’d probably pass on the spray though.
             
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            • rumblefish360

              rumblefish360 Well-Known Member

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              I like the idea of “Just a 400” low deck build.
               
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              • qkcuda

                qkcuda Well-Known Member

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                I made 415 HP and 450 TQ with a zero deck 400 with a mild 222/234 cam. You should be in the 425-450 range.
                 
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                • mcv

                  mcv Member

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                  Thanks for all the replies... the idea of just a "400" is what iam going for
                  Iam hoping for around 450hp at this point, should be fun.
                   
                • 33 IMP

                  33 IMP FBBO Gold Member FBBO Gold Member

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                  I think you can get 450 hp, but the rings will need AT LEAST .030. (I'd go .035).
                   
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