Reversing an offset/production piston

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I havent ever done it. It used to be thought there was a mechanical leverage advantage to swapping banks. This was true on paper, but from what I know, very little "night and day" diference or power increase was empirically seen. No noise associated with it, just supposed to be better for power, shorter on life span I think.
 
I've heard of people doing this on 383's. Has to do with the factory pin off-set. Makes the rod angle better. What it's worth for power or if all Mopar engines have the off-set, I can't say.
 
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.
 
On a flat top piston u only have to reverse the piston on the rod.They are slightly noisier.340S HAVE .100 pin offset, 318s the same till they went to pressed pin, all other mopar V8 still have some offset.I do this trick with any factory piston that Iam using over. The reasoning being there is less friction because of the change in offset.Newer jobber pistons do not have any pin offset, but are a slight performance increase. When swapping hi comp pistons(factory) bank to bank u will gain 2 tenths in the .25..........This trick also worked on brand x stuff, but not as well because off less offset........Kim
 
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