Details - Flipping Pistons earns 5,000 dollars - LITERALLY ??

I think it was the most probable to be the result fom weight that Visard removed from Tony's whole rotating assembly. He went nuts lightening the pistons,rods and crank.
As for piston flipping.... I think you'd get more results from adding a few performance parts stickers in the right places to reduce drag than flipping the pistons around.