Join Shelby Forums Today

'69 GT500 Engine Questions

Discussion in '1965-1970 Shelby Mustang GT350 & GT500' started by DAdams, Feb 7, 2012.

  1. Feb 7, 2012 #1
    DAdams

    DAdams Active Member

    Posts:
    28
    Likes Received:
    0
    Joined:
    Aug 2, 2008
    Location:
    Texas
    A friend of mine restoring his '69 GT500 has just learned that his block is not original nor is it a true CJ block.

    A couple of questions please.

    1- In searching for a replacement block what date codes would be considered "correct" for a car built December of '68.

    2- Exactly what intake manifold should be on his car. He has an iron intake however we are unsure what is correct for the '69.

    Thank you.
     
    DAdams, Feb 7, 2012
    DAdams, Feb 7, 2012
    #1
  2. Feb 7, 2012 #2
    Coralsnake

    Coralsnake Well-Known Member

    Age:
    60
    Posts:
    1,048
    Likes Received:
    16
    Joined:
    Sep 8, 2004
    Location:
    The Northcoast
    The intake should be the cast iron C80E-C.

    The block is usually dated within 30-60 days before the build date of the car.
     
    Coralsnake, Feb 7, 2012
    Coralsnake, Feb 7, 2012
    #2
  3. Feb 7, 2012 #3
    Snakepit

    Snakepit Well-Known Member

    Posts:
    843
    Likes Received:
    12
    Joined:
    Jul 3, 2005
    Location:
    Central Calif
    Checking the records I've got I see examples between 17 days and 79 days

    Good luck with the search
     
    Snakepit, Feb 7, 2012
    Snakepit, Feb 7, 2012
    #3
  4. Feb 8, 2012 #4
    DAdams

    DAdams Active Member

    Posts:
    28
    Likes Received:
    0
    Joined:
    Aug 2, 2008
    Location:
    Texas
    Great! Thank you both for the information. The search is on...
     
    DAdams, Feb 8, 2012
    DAdams, Feb 8, 2012
    #4
  5. Feb 12, 2012 #5
    DAdams

    DAdams Active Member

    Posts:
    28
    Likes Received:
    0
    Joined:
    Aug 2, 2008
    Location:
    Texas
    Re: '69 GT500 Engine Date Code

    We have located a couple of options regarding the block for my friends '69. One is dated 8J26 and another with a date code of 8M20.

    Initially it seems neither really fit the window for a 12/30/68 build date.

    Should we keep searching or pursue one of these?

    Thank you for the input.
     
    DAdams, Feb 12, 2012
    DAdams, Feb 12, 2012
    #5
  6. Feb 12, 2012 #6
    patty.dilabio

    patty.dilabio Well-Known Member

    Posts:
    327
    Likes Received:
    5
    Joined:
    Nov 26, 2006
    Hi Either of these 8J26 OR 8M20 Would be acceptable as they predate the car.
    J 26 is Sept 26 and M 20 is Dec 20 which brings the question which is in better condition ? A sonic check is mandatory to verify cylinder wall thickness.I would make certain this is one of the first tests done on a block you are considering.
    P.D.
     
    patty.dilabio, Feb 12, 2012
    patty.dilabio, Feb 12, 2012
    #6
  7. Feb 12, 2012 #7
    DAdams

    DAdams Active Member

    Posts:
    28
    Likes Received:
    0
    Joined:
    Aug 2, 2008
    Location:
    Texas
    Both blocks are standard bore. We've had some prior experience with both individuals so I'm pretty confident each would refund money if a defect was found at the machine shop. Only problem is one is out of state and involves shipping. The other is only a 3 hour drive but of course they want a premium knowing we're looking for a dated block. That's just the nature of the beast I suppose.

    Thanks for the help...
     
    DAdams, Feb 12, 2012
    DAdams, Feb 12, 2012
    #7
  8. Feb 13, 2012 #8
    Snakepit

    Snakepit Well-Known Member

    Posts:
    843
    Likes Received:
    12
    Joined:
    Jul 3, 2005
    Location:
    Central Calif
    Re: '69 GT500 Engine Date Code


    Looking at other casting dates (I think that is the dates you provided) the 12/20 look too tight to be a good choice IMHO - looking at casting dates and real build dates of other big block Dearborn cars to compare

    End of Sept is basically three months - a bit of a reach but possible IMHO
     
    Snakepit, Feb 13, 2012
    Snakepit, Feb 13, 2012
    #8

Share This Page