What kind of pit mix is this?

the shelter detto it was a lab pit mix to attract attention to it, but it now seems (weve had him for 6 months, Apache) he cannont be a lab mix, and we cannot figure out what it is. the mystery is the rising hips. many Cani dont have the rising hips and it seems to be a pit thing. also he has a reddish nose, which the picture doesnt mostra well. he is about 55lbs, lean and is one of the best listening, learning and playing dogs. hes great with kids, does tricks, and listens perfectly and be off a leash outside with no problems and will come to your side when te call him no matter whathes doing. what kind of pit mix is this?