Letter on position 1 (b) changed: 7 words corks dorks forks norks porks works yorks Letter on position 2 (o) changed: 4 words barks berks birks burks Letter on position 3 (r) changed: 6 words boaks bocks bonks books bosks bouks Letter on position 4 (k) changed: 5 words boras bords bores borms borts