The purpose of an offset wrist pin is to get the thrust face of the piston tight against the cylinder wall before the plug fires. If the ignition timing is set before TDC, the offset needs to be placed so the piston loads the cylinder wall before TDC. This means installing the piston with the offset opposite the direction of rotation. If timing is after TDC, the offset needs to go in the direction of crank rotation. If the plug fires while the piston is "floating" in the cylinder, you'll get a piston slap as the plug fires.
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!
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