When putting pistons on rods...

The biggest thing would be the fillet of the crank would chew away at the rod bearing. Not a good thing. If you put the pistons in backwards there may be clearance problems with the valves among other things.

Jack
why did your concerning catostrophic failure seem so casually toned when I read it? Lol

It's like, oh the biggest thing with WWIII we would ever face is nuclear warfare and an engine knock! No biggie!