Again GAP is doing the stupid "cuffed" vanity inseam sizing with these.
Here's a pic of two 30" long jeans, one pre-cuffed Selvedge and one not.
As you can see, the Selvedge jeans are ~2" longer than normal. So *size down* if you want to wear these uncuffed.
And, of course, they never carry "28" in-store (really, 30"). Stupid.