I got these pistons, and they are said to be OS .25 according to the number on the box and rings. I also read online that you can tell that they are OS if they have a large hump on the piston, and the standards are more flat. Here is a picture of the pistons. Anyway, I sold them being positive they are OS, but the guy sent me an email saying they are standard. Could somebody confirm if these are OS or standard before i refund this guy his money back. I just don't want this guy to have the Standards and buy my OS and then switch them and send me his set back. Here are the pics.

My Pistons I sold:


Thanks in advance!

 

this statement "I also read online that you can tell that they are OS if they have a large hump on the piston, and the standards are more flat." is totally wrong there should be a stamp on the top of the piston that says if its over sized if the pistons you sold were over sized it should have a .25 stamp on the top of it

 

Ditto.