340 Block Bored to 4.160????? Help

no. max bore on an X block is 4.140

Not so;

X blocks are NOT limited to standard production block limitations.

Current-ish, are they even around anymore?!?!?!
LOL! NOT! But the following race block part numbers;

p4876381/789/671/791/673/793 are 4.220 blocks.

All are 48* blocks except the '791/793. There 59*
The 789 is a 48* aluminum block.


So, what block does our OP have? He stated a 4.160 bore all ready.