Should the main bearing oil holes be misaligned? For the 312.

Yes

This is correct?
 

 

 

Hello who is the manufacturer of those bearings thanks .

I have been grinding the holes in the block to align with the bearings' holes for years.  Scribe the outline of the bearing hole into the block and grind to the scribed lines.

John - "The Hoosier Hurricane"

Back in the eighties, Ford was selling out all their NOS 427 parts. I was able to buy a new side oiler block in the box.  I was told these last blocks may have minor defects, so I carefully inspected it. I have always used Clevite bearings.  My 427 block had the oil hole misalignment like the block in your photos. Since then, I have seen a number of FE blocks with the same issue.   I enlarge the hole with a grinder to correct this.  I believe it's a fairly common issue.

Main bearing oil hole misalignment on the Ford Y is normal for mains #1, 2, & 4.  A die grinder will easily correct that if it’s a concern.  It’s always best to do any grinding to the block before it goes to the machine shop for any work though.  If new cam bearings are already in the block when observing this, then leave it alone.

Lorena, Texas (South of Waco)