'67 NADA engine question

[drc123]

I'm having one of my 2.6L's completely redone, a question has developed on the dimension for the main journal. Both the green bible and the NADA supplement report the journal is 2.625 inches, however when we put a micrometer on it, it is 2.5 inches, there is no wear or slop. Has anyone encountered this difference? Any insight / advice would be appreciated.

[o2batsea]

Is that with the bearing shells in place or not?

[Paul and Judson]

On page 51 of the NADA supplement it gives the "nominal" diameter. To us the key word is nominal in the sense of "approximate ". Just like a 2x4 is a nominal dimension.

[I Leak Oil]

1/8" That's a big difference! Make sure that spec is for the 6 cylinder first off. If so, perhaps it has already had some major machining in its past life?

[antichrist]

1/8" That's a big difference! Make sure that spec is for the 6 cylinder first off. If so, perhaps it has already had some major machining in its past life?
Good point about the right engine. 2.25 is 2.5"

For 2.6
Page 12-43
Journal diameter 2.6254 - 0.0005
Regrind permissible by .010 increments to 2.584