small block differences. someone want to fill me in please?

Rabius...I've kicked around this idea...and i've heard that you weaken the crank to turn it to a 318 size so...i figured...why couldn't you line bore the so many thousandths and Turn the crank and then you won't be weaking your main caps and y ou won't be weaking the crank...just something i thought of...but i think i'm gonna do it on a magnum 318 and run it in a dakota...