Piston identification

[Bill Bickle 15098]

I have four new pistons from a barn find. He dealt principally in Cadillacs and LaSalles but I can't identify them.  It says 556712 GM. Any help in identifying these would be appreciated.

[Steve Passmore]

If its a Cadillac box it should have a group number first.
Steve

[Warren Rauch]

  The part number makes no sense for Cadillac, Buick or Pontiac. I can only find the first three digits in Olds 8 's about 1950. That leaves GMC which I don't have numbers for that time period.
  Hollander lists pistons by size. If you measure diameter, length, distance from center of pin to the top,pin diameter, number of rings and type of metal (cast iron , aluminum,etc) There is a good chance to ID that way. Warren

[Chas Hillegass]

     
      Re piston #566712:

      I looked in my 1950's Oldsmobile parts books with little success, except that group 0.603 engine rod
      assembly clearly lists part # 566710 as a connecting rod for a 49 & 50 six cylinder olds. I would start my
      Hollander Interchange search there, as the number is close in sequence.  Hope this helps, Chas.

[Steve Passmore]

One numeral difference on a part number can mean its a World away in terms of what it fits.
Steve