Main Bearing Sizes

[68CoronetRT]

Does the main bearings only come in .010 under sized? This would be on a 440, 78' block. Also a cast crank if that makes any difference. In other words, once you pass the .010 undersized point of a crank, is that it for the crank?

[cdr]

,

[c00nhunterjoe]

You can get .020 under. But for the cost to cut polish and rebalance, you could buy a stroker crank. I wouldnt run past .010 even on a street build.

[John_Kunkel]

Sealed Power (#5025M) and Mahle both show .030" undersized wide-flange main bearings.

It's pretty common nowadays to grind the RB mains 1/8" under to fit the B block with no epidemic of failures.