Pistons with a "front" indication- - - -notched, "F" cast into the wrist pin boss, or something else, almost always have an offset wrist pin. That allows the thrust face of the piston skirt to be firmly in contact with the cylinder wall before the spark plug fires. Put one in backwards, and there will be a very noticeable piston slap at idle.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!