I'm glad to see former Green Bay Packers DE Michael Montgomery is returning to a 4-3 defense, but it's too bad he'll be playing for the Vikings. According to the Press-Gazette, he's probably signed for the veteran minimum of $630,000.
Just as DE Aaron Kampman wasn't a fit as a 3-4 linebacker, Montgomery wasn't a 3-4 defensive end. They tried to bulk him up to play defensive tackle in 2008, but he ended up playing a lot at defensive end after DE Cullen Jenkins got hurt and DE Kabeer Gbaja-Biamila was released. The coaches liked that he could play either end position in the 4-3, but I never saw the point since he was OK against the run and rarely provided a pass rush.
I don't know how badly the Vikings need depth for their defensive line, but now they've got it. He's a step up from the practice squad, but you'll know the wheels will have fallen off the Vikings defensive line if he becomes a starter.