Seven letter words change one or two letter to make a new word

girdled

bridled

riddled

griddle

gristle

degrade

degreed

You can’t go from gristle to degrade (four letters needed).

Playing off of “gristle”

bristle

twister

whistle

tillers

sillier

sullied

bullied

tallied

stilted

delimit

imbibed

dribble