I had some pistons pulled off(GSR) and the guy etched arrows in the rod(electric etcher) that showed which way the rods were suppose to go(I guess to fool-proof it?). Anyways, will these marks effect the strength of the rod? It's deep(or so I think, im no machinist or metallurgist), but im worried because people get their rods shotpeened to strengthen the "skin", but this now has a mark thats on the "skin".

 

Those marks can cause the rod to fail, as they are very efficient stress risers. Shot peening is a controlled procedure to compress the surface of the metal, etching is just plain dangerous for a stressed component like that.

 

Do you think shotpeening it now will fix it or should I just scrap the rods?