Flip that size and athleticism to the other side of the ball and the logic for offering King a college scholarship is apparent.
King got his offer to come play outside linebacker at Tennessee on Thursday.
"I called (Tennessee linebackers) coach (Peter) Sirmon because my coach actually got a text message from him," King told InsideTennessee.com late Friday night. "They talked for a couple minutes. Then, my coach called me and told me to call coach Sirmon real quick. I did that and coach gave me an offer."
Although UT was King's 14th offer, it was still a special moment for him, brother Jerry King Jr. and parents Jerry Sr. and Catherine King.
"I was shocked cause you know it's Tennessee and my brother plays football at Tennessee Tech," Justin said. "That was really flattering for both of us because we'd only be an hour away from each other and I could come see him play and my dad could come see both of us play. That's something my dad always wanted to accomplish to see us both play the same day in college."
Does an offer from a Southeastern Conference school like Tennessee mean King dwindled his list of favorites?
King has shown his gridiron skills and smarts by holding down several different positions on both sides of the ball for Dunwoody coach Jim Showfety, but plans on settling in at outside linebacker at the next level.
"That's my main focus right now is just being the best linebacker I can be at the next level," said King, who's ranked the 68th best player at his position nationally by Scout.com. "I'm just really working hard with my defensive coordinator (W.C. Davis) to teach me different schemes and different footwork, just being a great linebacker."
King said that he doesn't pattern his game after anyone specific but has become an admirer of high-motor NFL players like Green Bay linebacker Clay Matthews and Houston first-round draft pick defensive end J.J. Watt.
"I try to bring (Watt's) motor to the game and Clay Matthews just being so aggressive. That's what I try to install in my football skills," he said.
King plans to showcase some of those skills when he camps at Tennessee in mid-July.
"I'm just going to go up there and have fun and do the best I can with all the drills," he said.
The three-star prospect that dons No. 7 for the Wildcats is currently bench pressing 295 pounds and squatting 415.
In December, King was honored as the Crier/Wells Fargo Advisors Male Athlete of the Month after leading Dunwoody to wins over rivals Chamblee and Marist. He lit up the stat board with 413 yards rushing with three touchdowns on the ground and three more TDS through the air.
This season, King and his Dunwoody teammates plan to make some noise in the postseason in an attempt to unseat defending GHSA Class AAAA state champion Chattahoochee. That includes committing to a college soon enough so he can direct his attention to the present.
"I'm going to make a decision before my season kicks off so I can stay focused on my senior year, really just get to our goal and that's winning a state championship. Our senior class now, since we were freshmen, we've always promised to each other before we graduated that we were going to work hard, do the best that we can and get to that state championship and put another state championship in that Dunwoody area," he said.
King does not plan on enrolling in college early. He will enjoy his final year of high school with his friends, hang out in the film room with his Wildcat coaches and hit the weights.