1974 Doubleday and Co, hardcover, John Henry Reese (Big Mutt). The blowholers weren't really a gang, but a group of this vicious riffraff banded together just for the fun of it and killed a settler and savagely raped his daughter. They would have gotten away with it, if it hadn't been for Ownie Cope. The Born Loser.
Used availability for John Henry Reese's The Blowholers