Hello and thanks for reaching out. The inseam on a regular boxer brief is approximately 6 inches on body, so the long leg boxer brief is approximately 3 inches longer or approximately 9 inches on body. I hope this helps.
I'm not really sure but I'm 5'7" and over 250lbs (mostly gut) and they're very tight and uncomfortable. Made for the height/weight proportionate. If I were 6 feet tall they'd be great. Don't know if this helps but, one other thing... I would've preferred plain cotton to this silky material. Just my preference. Good luck.