NEW ORLEANS – The erstwhile missing piece on the 49ers' offensive line goes about 6-foot-8 and 300 pounds, topped by the hint of a faux-hawk haircut. Last season, he was hiding in broad daylight, appearing in short-yardage situations and on special teams.

Then again, it's a pretty big puzzle that Alex Boone has helped complete.

Each member of the the 49ers' offensive line – when not in a down stance – stands 6-3 or taller. In terms of weight, Boone is listed as the lightest man on a unit that bulldozed the way this season for the 49ers to gain 2,491 rushing yards (fourth in the NFL) on an average of 5.1 yards per carry (third).

"They're totally a different group than any team I think we've played," said Ravens All-Pro defensive lineman Haloti Ngata, who will line up across the way in Super Bowl XLVII on Sunday. "They're all big.

"They're kind of like Kansas City – their whole O-line was big and physical. But this team seems like they have a little more quickness, watching their film."

Mammoth quickness – it's a seeming contradiction – is typified by Boone, who has been a pleasant surprise for the 49ers in his first season starting at right guard.

Before this season, Boone, who signed with the 49ers as an undrafted free agent in 2009 and spent his rookie season on the practice squad, played tackle. But after right guard Adam Snyder signed with Arizona last spring, the 49ers opted to give Boone a shot at the starting job – despite the fact that he's unusually tall for a guard.

The move meant Boone would typically be battling bigger interior linemen, not lithe pass rushers off the edge, with less time to react to their moves. With the rest of the line returning intact, offensive coordinator Greg Roman said, there were "a lot of questions on that spot" and how Boone would handle the change.

"You have to really be able to play with great quickness, short-area quickness, balance," Roman said. "Things are on you quicker, a lot of twists, blitzes. … Somebody as long as Alex, you're not sure if he can play with that kind of quickness.

"It's something you have to see to believe, and the results have been just blowing us all away," Roman said. "Not only what he brings from a physical standpoint, but what he brings from an attitude, toughness standpoint just can't be overstated."

Boone and right tackle Anthony Davis played every offensive snap during the regular season, giving the 49ers stability on that side. It helped that Boone embraced the close-quarters struggles of what he called "a whole other world" on the interior line.

"It's what I do," Boone said. "I've always been a physical person. It took about a week (to get used to the adjustment), but after that it was all second nature."

Left tackle Joe Staley called Boone, who made his first career start in the season opener at Green Bay, a "catalyst" for a line that flourished in 2012. The website Pro Football Focus ranked the 49ers' the top run-blocking line in the NFL, while all five starters were named to the Pro Bowl – Staley and Mike Iupati as participants; Boone, center Jonathan Goodwin and right tackle Anthony Davis as alternates.

A run of good health – the 49ers were one of just three teams to start the same five linemen in every regular-season game – allowed their development to continue uninterrupted.

"Anthony and Mike, they really came into their own this season," Staley said. "And just the natural development of players and the process of working, I think that coupled with Boone's addition has made a lot of difference."

Boone may figure prominently Sunday in whether the 49ers can do a better job up front than in their 16-6 loss to the Ravens in 2011. Baltimore recorded nine sacks that Thanksgiving night, often exploiting the right side of the 49ers' line, and held San Francisco to 74 rushing yards on 21 carries. Two of the sacks came from Ngata, the agile, 340-pound tackle whom the Ravens shift along the line.

"I remember a couple communication problems, remember at times blitzes weren't seen properly," Goodwin said. "Whether it be running back, offensive line, it was almost like the perfect storm of stuff.

"Hopefully, we've learned from some of that stuff, and I think we have through the year gotten better."

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