6 inch rods in a 400 small block?

Discussion in 'Engine Topic' started by dans2ndgenfbody, Sep 14, 2006.

  1. dans2ndgenfbody

    dans2ndgenfbody Veteran Member

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    What all is required to install 6 inch rods into a small block 400. Is it just a custom piston? Can I reuse the stock crank? What is a rod that will work? Is it easier to install a 5.7 inch rod into the 400?

    Iam using AFR 195 street eliminators a victor JR intake havent chosen a cam yet and am just going to 30 over the 400 but I want to get the rod length up as I hear that the stock rods are a little on the short side.

    I am also going to use some nitrous on the motor from time to everytime.

    Any info appreciated. I tried to search posts on "400" and "rod length" and spent hours sifting through but found no exact info.

    Thanks.

    Dan
     
  2. hardline_42

    hardline_42 Veteran Member Lifetime Gold Member

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    6" rods can and are often used on 400's. You will need pistons with the correct compression height and some clearancing of the rods to clear the cam. If you plan on using the stock crank, it may have to be clearanced to work. Most 6" rods are used with a specific aftermarket crank .
     
  3. dans2ndgenfbody

    dans2ndgenfbody Veteran Member

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    Then can I use some 5.7 inch rods from eagle/scat and the stock 400 crank polished/ground and some J/E pistons for this application and have no worries?
     
  4. onovakind67

    onovakind67 Veteran Member

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    Yes you can, at least no worries about the rotating assembly if it is used in a normal application. I have 5.7" rods and KB pistons on a stock crank in my 406 and they work well.
     
    Last edited: Sep 14, 2006
  5. dans2ndgenfbody

    dans2ndgenfbody Veteran Member

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    thanks. cause i dont mind buying a different set of rods and some forged pistons but i wanted to use the crankshaft that I have, then just have it all balanced.
     
  6. onovakind67

    onovakind67 Veteran Member

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    If you have any problems with your crank I have several of them in my garage here in Fairfield.
     
  7. dans2ndgenfbody

    dans2ndgenfbody Veteran Member

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    what do you want for one?
     
  8. rustbucket79

    rustbucket79 Veteran Member

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    The only time you need 6" rods is when you have an aftermarket crank that has larger counterweights designed for the purpose of internal balancing the 400 /383 crank. Since you are staying with the factory crank an inexpensive Scat I beam rods are a good choice. Pop for the capscrew rods, they are easier to clearance for the camshaft. 2-ICR5700 for full float pistons, 2-ICR5700P for pressed pin style pistons. Better bolts, more material around the big end, and they are lighter than stock rods, and not much more expensive than adding ARP bolts to stock rods.
     
  9. dans2ndgenfbody

    dans2ndgenfbody Veteran Member

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    thanx
     
  10. KylePBZ

    KylePBZ Veteran Member

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    If you haven't bought a cam yet go with the 6" rods then just get a small base circle cam.

    I have two buddies that both have almost identical 406's. 6" rod, flat tops, AFR 195's, solid flat tappet cams in the [email protected], 550ish lift, RPM Air Gap intakes, 650 and 750 Demons. One is a 81 Monte, the other is a 83 Z28. Both run 7.20'[email protected] in the 1/8th.

    Damn good combo IMO.
     

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