Stamped letters on top of block

[scout_77-ihc]

392 IC, what do the letters that are stamped under each cylinder on the top of the block? Mine has "A" and "B"? What does this mean?

Thanks,
Jason

 

[1975IH200]

The one is the "B" hole and the other one is the "A" ......oh never mind.

 

[Robert Kenney]

The letters indicate the finished bore size so final assembly engine builder can fit a piston of a size for optimum clearance. This is how IH controls and streamlined the engine assembly process.
this method is common in many OEM operations.

 

[scout_77-ihc]

So if these letters are still visible does this mean "if" the previous owner had portions of the engine rebuilt, then it is unlikely that they had anything shaved off the top of the block?

Thanks,

Jason

 

[Robert Kenney]

I would say it has not been decked. Decking is not necessary for a rebuild unless it is not flat or has damage.

 

[scout_77-ihc]

Good to hear, I am in process of rebuild now. Thanks for the help.