NORTH BILLERICA – It wasn’t quite perfection, but for the defending Division 3 North champions the outcome was still what they wanted.Led by two goals by Ryan Dempsey, Marblehead overwhelmed No. 5 seed Dracut, 5-1, at the Chelmsford Forum on Thursday to reach the Division 3 North finals for the third time in four years. The Headers will face top-seed Shawsheen, which beat Wayland, 3-2, in a shootout in the other semifinal, Saturday at 5:30 p.m. at the Forum.”The last two game, we’ve gotten goals from all three lines and that makes a big difference,” Marblehead coach Bob Jackson said. “You can’t just key on one line. It’s nice to see the kids work hard and score.”Marblehead was on its game from the start, outshooting the Middies 15-6 in the first period. They used a two-goal outburst in 23 seconds late in the period to go ahead for good.Dempsey got Marblehead on the board at the 9:37 mark off a nifty centering pass from Hunter Graves. On the very next shift, Tom Koopman (3 assists) set up Ian Maag for his eighth goal of the season and a 2-0 Marblehead lead after one.The Headers kept the heat turned up, as Dempsey notched his second goal of the game at the 4:19 mark when he jammed in a Jake Kulevich rebound. Dracut made things interesting late in the period when Shaun Conley’s slap shot got past a screened Tony Cuzner with 3:52 left. Marblehead, however, got the goal back with 40 seconds remaining when Ty Bates slid in a rebound to make it 4-1 after two.”This game was a product of our bad third period the other night,” Jackson said. “To a man, everyone was disappointed with how we finished against Latin Academy. Tonight was the result of that.”The Headers avoided a third-period let-down as they outshot Dracut 11-6 and closed the scoring on Chris McLeod’s 20th goal of the season.