The block was decked and ended up an average deck height of 0.005 on right and 0.002 on the left. Since the pistons within one bank are close to one another the deck appears to be OK.
Before I removed the 2 pistons, I figured I would recheck them... The measurements aren't repeatable enough given the target. I very carefully remeasured all 8 two more times turning crank only in one direction, and got different answers.
So I decided to complicate things and tried to identify why.
1) I tapped on the front of the piston to take up any slack and measured the front and back depths.
2) I then tapped the back side of the piston and measured the front and back depths again.
The pistons can rock about 0.012 along wrist pin. This slack/uncertainty is beyond pass/fail limit.
For example cylinder #1
measured a front back difference of 0.000 in condition 1, and then a difference of 0.013 in condition 2.
Taking average/center of the two of measurements, I get the following;
where a positive number is front of piston lower than rear. Note that all right bank are tilted in same direction (back) and left bank all the other way.
So it appears I either need to replace all the rods or run it as is. The assembly was balanced so a new rod set would need to be lightened accordingly. I'm concerned that a different set of stock rods may not get me to 0.002 or better.
I pulled #2
out and verified that the pin-to-crown measurement was the same on front and back of piston, it was right on.
What is the correct procedure for this measurement? Who actually measures this?
EDIT: I wanted to see the effect of the big-end end play at the piston crown. Moving the big end of the rod back and forth on the crank journal the end play amount (about 0.010) moves the piston tilt about 0.006-8. This indicates that most of the slop is on the big end. Not useful, just an observation.