Reversing an offset/production piston
This was a common practice to install the pistons in a B/RB upside down some years back. It was a performance trick that the Mopar guys did racing in Stock Class. It's not a night and day difference in power but every little bit helps in class racing. What it did was it made the piston dwell at Top Dead Center longer. The only draw back was that the pistons "rattled" in the bores. I have not heard of any one doing this to small blocks, so I assume that the small blocks don't have an offset wrist pin. The reason that Mopar made the wrist pin offset was to make the pistons quietier because of the larger bore. The larger bores require more piston to bore clearance which can translate into a noisier motor. A noisy motor would not be very desirable in a Chrysler New Yorker, Imperial, etc.