With Josh McCown getting the start at quarterback, the Raiders began their 2007 campaign at home in an interconference fight with the Detroit Lions.  After a scoreless first quarter, Oakland trailed early as Lions QB Jon Kitna completed a 13-yard TD pass to WR Roy Williams.  Detroit would increase its lead before halftime with kicker Jason Hanson getting a 46-yard field goal. In the third quarter, the Lions continued with their early lead as Kitna completed a 16-yard TD pass to WR Calvin Johnson.  Afterwards, the Raiders began to come back as McCown completed a 4-yard TD pass to WR Ronald Curry, followed by RB LaMont Jordan getting a 12-yard TD run.  In the fourth quarter, Detroit responded with Hanson kicking a 46-yard field goal, while Oakland took the lead with McCown completing a 7-yard TD pass to FB Justin Griffith.  However, as it seems to be for the Raiders, their lead wouldn't hold as the Lions scored 17 unanswered points (32-yard TD pass from Kitna to WR Shaun McDonald, Hanson getting a 23-yard field goal, and RB Tatum Bell getting a 14-yard TD run) to end the game.
Question: How many more yards was the touchdown pass to Roy Williams.over the one to Justin Griffith?
Answer: 6