The 402 isn't a 396 punched 0.030 over...

[davepl]

Riddle me this:

The bore on a 396 is 4.094
If you punch it 0.030 over, you're at 4.124
The bore on a 402 is 4.125
Where'd the extra thousandth go? Does it matter?

For example, if you buy 0.30-over pistons for a 402, they'd be 4.155, but if you punched the 396 0.060 over, you'd be at 4.154

It's only one thousandth of an inch, but it still bugs me. Does a thousandth of an inch on piston diameter matter?

When I build an engine I shoot for 0.003 to 0.005 piston to wall clearance, so that's probably all that matters, and so I figure that missing 0.001 is within clearances. Safe assumption?