Identification, VIN, Trim, Engine Specs and more... 
 '50   '51   '52   '53   '54   '55   '56   '57   '58   '59   o 
 p 
 e 
 n 
 '60   '61   '62   '63   '64   '65   '66   '67   '68   '69 
 '70   '71   '72   '73   '74   '75   '76   '77   '78   '79 
Canadian car identification here: Serial Numbers 1935-1964 | 1965-1966
and more information in the reference section here.
Results 1 to 3 of 3

Thread: Casting numbers 401/425

  1. #1
    Join Date
    Feb 2008
    Posts
    8
    Rep Power
    0

    Casting numbers 401/425

    Although the 401 and the 425 nail head is almost idential I have read that you cannot bore a 401 to a 425 . The casting numbers are different for the 401 and the 425 with one exception : number 1364705 for 1964 through 1966 is designated as 401/425 . Does any one have any information on this engine block casting ? Why it was made , were it was used etc.

  2. #2
    I have read that you cannot bore a 401 to a 425 .

    depends on core shift. the 1/8" or .125" bore difference is a huge overbore for a thinwall casting block but the Nailheads are either before thinwall casting or the first iteration of thinwall that Buick did. they are a bit more robust than the later BBB and SBB designs.

    you would still have to have any 401 block sonochecked for cylinder wall thicknesses before you ever even considered doing something like that though.
    The way to crush the bourgeoisie is to grind them between the millstones of taxation and inflation.
    Vladimir Lenin

    Government schooling is about "the perfect organization of the hive."
    H.H. Goddard, Human Efficiency (1920)

  3. #3
    Buick was one of the 1st. to start using the thin wall casting method. This started in 1957. No Way, No How can you safely bore a 401 to a 425 bore. You MUST HAVE THE BLOCK SONIC TESTED!!!!!!! Even then it's kinda iffy.

    Tom T.

Similar Threads

  1. foundry casting numbers
    By 32special in forum Straight Eights!
    Replies: 4
    Last Post: 05-18-2013, 11:54 AM
  2. '63 401 crank casting numbers
    By chuckw2 in forum Buick Identification and Decoding
    Replies: 4
    Last Post: 02-10-2009, 07:26 PM
  3. do you have your casting numbers
    By wizman383 in forum Tools, Shops, and Garages
    Replies: 1
    Last Post: 11-22-2005, 07:35 PM
  4. head casting numbers
    By kiwipetrolhead in forum Small Block 215, 300, 340 (and Rover V-8)
    Replies: 2
    Last Post: 10-01-2003, 02:36 PM
  5. Casting numbers?
    By jforb in forum Nailhead: 264, 322, 364, 401, 425
    Replies: 2
    Last Post: 11-10-2001, 04:44 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
TeamBuick.com Privacy Policy