Any Old School Machinists Here?

The thing being missed is the O/P wants to use aftermarket main caps.... So the need to line bore is real... The trick is to barely touch the top of the bore.....

Not sure what caps are being used but some brands need a lot of material removed to get the bore diameter where it needs to be...

If your removing material from the block while correcting the cap your gonna create problems..

A friend was recently trying to fit billet caps to a Hemi block & the mismatch was bad enough they used a junk 440 block to act as a jig while they did 90% of the roughing before moving the caps to the Hemi block.... And yes, that required milling out the junk 440 block to accept the cross bolt bosses.. It was more work than it was worth but there was already to much work done to the Hemi block to stop....