ordered a box of pistons, got oversized

Anyone had recent experience with oversized pistons? Ordered some new pistons and got a mixed bag of #2 & #3 pistons. Years ago, I found that a #3 would lock up a Super Rat motor once it got hot. Made some measurements & found that each number indicates 20 micrometers larger piston, so a #2 is 40 mics larger than stock & #3 is 60 mics larger.

Not sure if Super Rat is bored tighter than others, so am wondering if these will run OK in new cylinders or if they are only for use in used cylinders.

I have seen standard which is blank, and #1, #2, #3, and #4. Some right from the factory in the motor. Not a big diff, as you have to get all the way up to #4 to see one 3 thousandths inch larger. But we did see a new Super Rat seize when a #3 got hot, then run well on a standard piston (that motor came with a #3 installed at the factory)..