Usually the arrow points towards the front. However, this isn't
sacred, I've seen pistons that went the other way. If a mfr wants to
point it towards the rear and makes it clear to the assembler, OK. Got
to assume the short-block assembler knew what he was doing.
There's an oil squirt hole in the con-rod. It must face towards the
correct side of the engine. So you can't turn the whole assembly
around. Unless I knew for sure that it was incorrectly assembled, I'd
put it back together the way it was.