I am attempting to rebuild my 302dz engine and noticed that the pistons are very clean but have
scratch marks or file marks on all the edges. Anybody know what this might be caused by or why it would have been deliberately done (for racing perhaps)? Any info greatly appreciated, thanks.

send the pistons and the rest of the engine to me and I'm sure in a few years I'll be able to tell you :rolleyes:

sounds like someone tried to cross hatch the pistons or really messed up doing the walls.