Did I see it right that the ring was still in, but one side had worked its way out? If this is the case, it is quite likely that the ring wasn't seated properly. Just letting the ring snap in place isn't enough if the grive is a tight fit. it is good practice to tap the ring home after getting it in the grove. A snap ring should be slightly loose in the grove. Just a thousands or so clearance on the OD of the ring. It should be a tight fit on the sides, not a press fit, but very close to it. The clearance on the OD is to allow for expansion.

I've never seen an application where the location of the lugs was fixed. As long as the ring is fully in the grove, it doesn't matter where the gap is.

Prior to assembling the engine, test fit the rings into the piston. Make sure there is no flashing or crud in the grove. Also, check the wrist pin for fit and for burs. The wrist pin should float between the rings, not be tight. You may need to stone the ends of the wrist pin if there is a rough finish on them. Just make sure it is well cleaned after so none of the stone is trapped in the center hole.

Don

D