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258 engine

Discussion in 'Intermediate CJ-5/6/7/8' started by mcknight1978cj5, Feb 22, 2010.

  1. mcknight1978cj5

    mcknight1978cj5 mcknight1978cj5

    I have a engine out of a 1978 cj that has a cracked block. Would the head match a block from 1987 ? Please no mean replies. I'm really needing help with this. Thanks,
    James
     
    mcknight1978cj5, Feb 22, 2010
    #1
  2. hudsonhawk

    hudsonhawk Well-Known Member

    The head studs may be a different size requiring sleeves. But other then that it should work.
     
    hudsonhawk, Feb 22, 2010
    #2
  3. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    No mean replies here.

    Yes, the '78 head will fit on an '87 block. The only possible mismatches will be the head bolt diameter (7/16" vs. 1/2" IIRC) and possible oil passage alignment. The oil passages will line up if both engines have stamped rocker arms, and both '78 and '87 should have 1/2" head bolts.

    Some of the later AMC 6 crankshafts have a different sized pilot bushing pocket, but I think that's limited to the 4.0L engines, not the 258.

    You should be ok.

    What's the story with the '87 block? 258s are not scarce or particularly desirable, so you should be able to find a complete used engine for not much money.
     
    timgr, Feb 22, 2010
    #3