Piston and rod bearings installation

IIRC, 273 2bbl pistons have 4 valve reliefs, so it looks like they can go either way. But there is still a front and a back for each piston -- the piston pin is NOT centered in the piston. The "extra" valve reliefs are just because they didn't want to cast different pistons for the left and right banks -- you just "turn them around" for the other side.

I've heard of the reversing the piston trick, but I don't think it's worth the wear and tear (piston slap) on a stock 273.

The hi-compression 273 domed pistons are different for each bank, since the dome is off-center and they only have one set of valve reliefs. These you definitely cannot reverse, except by swapping side to side.