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hemi tech, are 241 and 325 hemi heads interchangeable?

Discussion in 'The Hokey Ass Message Board' started by tunescape1, Oct 13, 2009.

  1. tunescape1
    Joined: Oct 7, 2009
    Posts: 25

    tunescape1
    Member
    from toronto

    can you put 241 hemi heads on a 325 block? i really need help on this
     
  2. tunescape1
    Joined: Oct 7, 2009
    Posts: 25

    tunescape1
    Member
    from toronto

  3. A Little Odd
    Joined: Aug 10, 2006
    Posts: 347

    A Little Odd
    Member

    I can't help but I know this has been discussed I think. Try the search...
     
  4. Try Dodge Hemi Interchange in search. Is this that deal with the 241 that needs a rebuild and the 325 short block? Make sure that short block is a hemi, the pistons are different, you might bang them off the valves if they're poly.

    I can tell you that the 241 heads will bolt to '55 Plymouth 241 and 259 poly V8s, which are the only year the Plymouth V8 was a block that was shared with any Hemi.
     

  5. Yes.... you can install 241 Hemi cylinder heads on a 325 block.
     
  6. 35desoto
    Joined: Oct 6, 2009
    Posts: 773

    35desoto
    Member

    Yes "drylakeswheel man" is correct
    There are some valve size and port size differences however the heads interchange and work.
     
  7. tunescape1
    Joined: Oct 7, 2009
    Posts: 25

    tunescape1
    Member
    from toronto

    and i wont need any spacers(intake off the 241) being that the 325 is a raised deck block?
     
  8. tunescape1
    Joined: Oct 7, 2009
    Posts: 25

    tunescape1
    Member
    from toronto


    i have checked and the 325 is a hemi block and it looks brand new the pistons still have the factory etch in them
     
  9. tunescape1
    Joined: Oct 7, 2009
    Posts: 25

    tunescape1
    Member
    from toronto

    and ive heard ill need raised deck push rods?
     
  10. 73RR
    Joined: Jan 29, 2007
    Posts: 6,710

    73RR
    Member

    You can, but why would you? The 241-270 have pretty small valves. The 315-325 poly head would likely make more power on a 315-325 than the 241 head.
    Tall deck Dodge requires tall deck intake.

    Side note: Dodge and DeSoto tall decks used different intake manifolds than the short deck engines. Chrysler engine intakes will fit both short and tall deck because the intake port location was moved in the 392 head to accomodate the 354 manifold. This is why an intake spacer is needed if you put 331-354 heads on a 392 block. If you put 392 heads on a 331-354 block then a one piece intake will not fit, you will need a 2-piece log type manifold.

    .
     
  11. tunescape1
    Joined: Oct 7, 2009
    Posts: 25

    tunescape1
    Member
    from toronto


    i am asking because i have a basicly brand new 325 hemi short block and a 241 red ram with tri power so im trying to use the parts i have
     
  12. 73RR
    Joined: Jan 29, 2007
    Posts: 6,710

    73RR
    Member


    The thought process is on target, but try to find better pieces to work with. There should be plenty of poly heads available at bargain prices.....everyone wants to convert to Hemi heads. If you have to have a Hemi (no problem with that) start looking for 56-57 heads and 56-57 intake. It will be a better package and you will be happier (by comparison).

    Where are the valve notches in your pistons? Photo?

    .
     
  13. Weasel
    Joined: Dec 30, 2007
    Posts: 6,693

    Weasel
    Member

    Read here and you'll find out why...

    Here's a link to the first part, but you should read all of the series. Everything you ever wanted to know about building a Red Ram hemi:


    http://www.webrodder.com/article.php?AID=164&SID=4&CID=

    John Beck who built the engine is not only a fantastic race engine builder, but also a hot rodder, Bonneville racer and all time good guy - he walks the walk.
     
  14. George
    Joined: Jan 1, 2005
    Posts: 7,521

    George
    Member

    Did I see the short block for sale? The 241 heads will fit the 315/325 but the oil sealing surface along the top of the head is marginal.
     
  15. tunescape1
    Joined: Oct 7, 2009
    Posts: 25

    tunescape1
    Member
    from toronto

    i dont know if you saw it for sale, can you explain to me what you are talking about? the oil sealing surface along the top of the head???

    thanks
    matt
     
  16. Screamin' Metal
    Joined: Feb 1, 2009
    Posts: 506

    Screamin' Metal
    Member
    from Oklahoma

    Yes...............they're interchangable.............
     
  17. tunescape1
    Joined: Oct 7, 2009
    Posts: 25

    tunescape1
    Member
    from toronto

    what is needed? can i use the intake off the 241 or do i need one off a 325 or can i use spacers? what about the push rods? can i use the 241's or do i need 325's?
     
  18. George
    Joined: Jan 1, 2005
    Posts: 7,521

    George
    Member

    You need a high deck 325/315 intake on a high deck block. No spacers needed. Did you follow the webrodder link to see how they put 241 heads on a 315? If you tried to use the 241 intake you'd need spacers, not sure if anyone has tried that.
     
  19. George
    Joined: Jan 1, 2005
    Posts: 7,521

    George
    Member

    On the Webrodder Form Doc was saying that there isn't much matching surface where the top of the head meets the top of the block(above the push rod holes) & it would be easy to get an oil leak there. 270 heads are a little meatier & 315/325 are designed to fit, obviously.
     
  20. RichFox
    Joined: Dec 3, 2006
    Posts: 10,020

    RichFox
    Member Emeritus

    Seems like the 241 combustion chamber would be much smaller than the 325s chamber. Should be good foe a compresion increase. I wonder how much?
     
  21. lolife
    Joined: May 23, 2006
    Posts: 1,125

    lolife
    Member

    You can't use the 241 intake unless you make some spacers. No one sells them (it's a Dodge).

    For push rods get the adjustable ones from Hot Heads.
     
  22. Andy
    Joined: Nov 17, 2002
    Posts: 4,845

    Andy
    Member

    Spacers are impossible because the angle on the surface. You would end up with a jog in the passage and the bolts would have to be jogged as well. You need the high deck manifold,and pushrods. The dowels will have to be changed as well. Don't expect it to run very strong without a lot of intake port work. The combustion chambers were all the same volume except for changes due to valves. When I tried some 241 heads on a 325 hemi block, I ran into problems and gave up.
     
  23. TR Waters
    Joined: Nov 18, 2006
    Posts: 1,439

    TR Waters
    Member
    from Vermont
    1. Early Hemi Tech

    The 241 heads are cast differently on the gasket mating surface in the pushrod area. I have heard of people using a bead of silicone along the top edge (pushrod hole area), or you could build up that area on the heads themselves with epoxy. BUT, as said, you would be way ahead of the game by finding the tall deck heads and intake.

    No one makes an intake spacer because it would have to be well over an inch thick to get any type of port alignment at all.

    The circled area is where the 241 head casting differs.
     

    Attached Files:

  24. tunescape1
    Joined: Oct 7, 2009
    Posts: 25

    tunescape1
    Member
    from toronto

    alright, ive spent countless hours looking for 325/315 heads and intake and have come up empty handed, anyone out there have 325/315 heads and intake that they might want to get rid of? also anyone interested in a 241 hemi with tri power??
     
  25. Von MoPar
    Joined: Jun 4, 2006
    Posts: 359

    Von MoPar
    Member
    from Australia

  26. George
    Joined: Jan 1, 2005
    Posts: 7,521

    George
    Member

    between this link to the forum & the link on pg 1 to the article, I'd say this is covered!
     

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