It's been mentioned in this thread numerous times that it's to help compression, but it surely doesn't. And the angle the rod pushes on the crank changes throughout the stroke, so I doubt that amounts to anything either
If the .060 offset was the equivalent of a .060 longer rod, you’d be damned hard pressed to find a single horsepower by flipping it around. Going from a 5.700 to a 6.000 or even a 6.125 rod needs more than just a rod change to find any real power. It’s not just change one magic thing and you start knocking down records, winning all the trophies and kissing the girls.
Just flipping the piston would be way outside of measurable error on any dyno.