550 are a relaxed fit, 501 and 505 aren't so it kinda makes a big difference which number fit you have.
Also, what Lee's do you have?
550 are the Jerry Seinfeld fit and not as tapered as lots of the current baggy skate pants. For me the fit of baggy shit has to be on point otherwise I look dumb as hell. The new 93s don't fit me too well as the crotch ends up way too low, but if I size up a waist size in normal Carhartts the proportions are appropriate.