for a pontiac 400 and pontiac 455....and where do i find it

 

my 400 is still sitting right behind me in living room...
On the 400 look behind the passenger side head. the casting number is on the block there. post what it is and I can tell you what you have. It will also have 400 on the middle of block on passenger side and on the front part of the side of the block on drivers side. Not sure about the 455 but i can find out. block casting should be in the same place. Out of curiosity post the # of the heads, like to know what they are also.
Bob
Poncho man

 

And the block codes are usually a two- or three-character format, like "WX" or "WZ4" (just like the head codes). You can find a little bit of the list here:

http://www.yearone.com/updatedsingle...ontengid4.html