It's just one of those things that wasn't worth gambling on in my opinion. There are requirements in all industries for metallic strength etc. etc. Aircraft and aerospace especially. My motor was sitting under a deck for 4 years and the connecting rods were getting cut and resized so it was a worry-free must for me.
The best place for your question would be at
www.shotpeener.com
It's basically like a classicolds forum, only it's about shotpeening.
Here is the email address for expert answers to questions about it.
jack.champaigne@shotpeener.com
Hopefully, We'll all learn more from your question.