What is the purpose of this tab/ hole?

[oldmodlover]

Left side of pan rail behind water pump.

 

[dak**rt]

Not 100% sure but I think its a locating tab for when they machine the casting.

 

[moparmat2000]

My 2.2 blocks have a pair of those locating holes. That is the datum location. All dimensions for machining everything are located after these holes are machined into the block, and the block is set into dowel pins corresponding with the holes.

 

[oldmodlover]

Ok guys. I thought it may be something along that line. Makes sense. Thanks.