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Technical What to do, when you put 48 heads on a 49 flathead?

Discussion in 'Traditional Hot Rods' started by Larsdk, Nov 1, 2013.

  1. Ive seen several places, that you can use 48-42 heads on a 49-53 flathead, with minor modifications.
    But what modifications?
    I have looked in the Tech archive, but cant find anything.
    The same question goes for the manifolds.
    Please enlighten me.

    Lars
     
    Last edited: Nov 1, 2013
  2. Good question. I'll wait with you for an answer. I do not think there is a difference .
     
  3. CheatersPete
    Joined: Sep 25, 2002
    Posts: 1,290

    CheatersPete
    Member

    Plug the upper holes of the water pumps
     
  4. J'st Wandering
    Joined: Jan 28, 2004
    Posts: 1,772

    J'st Wandering
    Member

    Compare the '48 heads on the block and find the offending water passage. One hole on the top front of the block on each side needs to be plugged. I have not done it but that is what I was told.

    Regarding the manifold. I assume you are talking intake. Use bolts where there are holes that match to the block. Holes in the manifold that don't match to the block are not used.

    Neal
     

  5. Dale Fairfax
    Joined: Jan 10, 2006
    Posts: 2,585

    Dale Fairfax
    Member Emeritus

    I plugged the two water holes-kept the plugs (especially the passenger side) flush with block. Sawed out a piece of aluminum about 5/16" thick, drilled and countersunk it for two 1/4-20 flathead screws and drilled and tapped it for 5/16-18. Placed it on the block in the spot where the 8BA head's distributor hold down pad was then transferred the two 1/4 screw holes to the block. Drilled and tapped, covered the area with Permatex along with the two tapped holes and fastened the aluminum to the block. Simple-probably not more than 1 1/2 hours. Now I can clamp the distributor the same way it was with the late model heads and still loosen it to adjust timing without getting my fingers in the fan. (Which is the problem with a set screw in the timing gear cover.)
     
  6. Is it possible to see some pictures?
    Lars
     
  7. HotRodMicky
    Joined: Oct 14, 2001
    Posts: 1,783

    HotRodMicky
    Member

    You have to put plugs in the heads,too
    I think
     
  8. CheatersPete
    Joined: Sep 25, 2002
    Posts: 1,290

    CheatersPete
    Member

    No plus on the heads needed
     
  9. manyolcars
    Joined: Mar 30, 2001
    Posts: 9,176

    manyolcars

    Why do this when the right heads are so easily found?
     
  10. khead47
    Joined: Mar 29, 2010
    Posts: 1,789

    khead47
    Member

    I think HotRodMickey meant spark plugs!
     
  11. because i like the look of the 59A over the 8BA, and i have a french flathead.
    Lars
     
  12. arkiehotrods
    Joined: Mar 9, 2006
    Posts: 6,803

    arkiehotrods
    Member

  13. Thank you, that was what i was looking for.
    Lars
     
  14. HotRodMicky
    Joined: Oct 14, 2001
    Posts: 1,783

    HotRodMicky
    Member


    No, npt plugs.

    And i plug one side in the head,too
    Cause the gasket hole doesnt match the block.
    I just dunno wich side.
     
  15. driver side front
     

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