Got a 421 cub. Had 2 Wiseco 573 pistons that went in it during a rebuild, and had one cylinder go down. Buddy had a 421 cub that had some Wiseco 573's in it that were only ran a few passes then tore down and went to a builder and got some different piston. Well I just figured I'd run one of his pistons. But the pistons that came out of his motor had a small machined ring below the bottom ring groove. It was maybe .005" taken off all the way around the piston. Anyone know of a builder that does this? Think it will be an issue being a different weight than the other piston? I don't think the ring itself will, but I'm now worried that the piston may be machined somewhere else. We looked them over real good and they didn't appear to be different, hoping someone here knows of a builder that does this, and knows if they do any other machining on them.
Here's a pic of it, the machined section is between the red lines.