Help with identify Nailhead

Discussion in ''Da Nailhead' started by fruck, Apr 13, 2015.

  1. fruck

    fruck Member

    Is there anyone who could help me to figure out if the engine is a 401 or 425?
    The car is a Buick Electra convertible 1965 but I dont know if its the original engine or if has been swapped earlier.

    As you can see at the pict the code at front passenger side is ending with 529 and there is a W before but there is something between and even before the W..
    The casting number ends on 704= 425?
    I thought I read somewhere that convertibles only hade 401, wrong?

    Thanks in advance!

    Attached Files:

  2. Babeola

    Babeola Well-Known Member

    If that is a KW, it is a 1964 single 4bbl 425.

    Cheryl :)
  3. Babeola

    Babeola Well-Known Member

    Also, the casting number is listed for a 1963-1966 425 here. The 401 and 425 share some external casting numbers, but yours is exclusively related to the 425.

    Cheryl :)
  4. fruck

    fruck Member

    Ok... so you think its a 425. My casting number on the intake manifold are 1375549 cant find it in the document?
    Last edited: Apr 15, 2015
  5. Babeola

    Babeola Well-Known Member

    That casting list is not all inclusive, but what is there is correct. I clearly see KW and the date code in you other picture. That also represents a 425 (1964 single 4 bbl) as listed here. So, your cross check also indicates 425: Enjoy it! I would next check the numbers on the driver side of the valley pan rail and see if they match the last portion of you vin number. This way you know that is the original engine in the original car.

    Cheryl :)
  6. fruck

    fruck Member

    Now with this information I have order a new carburetor
    thanks for the information :TU:
  7. snake

    snake Well-Known Member

    If you look toward the back of the block just below the distributor if it's a 425 it will have a square trapezoidal hump next to a tear drop shape

Share This Page