The intensity level could hit an all-time high when the rugged Seattle Seahawks and San Francisco 49ers, who form one of the National Football League's fiercest rivalries, meet on Sunday for a spot in the Super Bowl.

The teams share the West Coast, the NFC West division, and are mirror images with mobile quarterbacks directing offenses with power running backs and ferocious top-five defenses that enjoy intimidating with bone-jarring hits and trash talking.

Personal rivalries in the NFC Championship game run from quarterbacks Russell Wilson of Seattle and San Francisco's Colin Kaepernick, who both carry chips on their shoulders from feeling overlooked in the NFL Draft, down to the head coaches.

Jim Harbaugh of the Niners and Seattle's Pete Carroll have been rivals since doing battle as college coaches in California when Carroll was in charge of powerhouse University of Southern California and Harbaugh turned Stanford into a power.

The Niners, who lost a heartbreaking 34-31 decision in last year's Super Bowl to the Baltimore Ravens, are the NFL's hottest team with eight straight wins but are on the road as a wild card team after finishing second to Seattle (13-3) in the NFC West.

SEATTLE NOISE

Seattle have been virtually unbeatable at home with the backing of their formidable '12th Man,' the raucous CenturyLink Field fans who set a Guinness World Record for crowd noise in December.

Harbaugh tried to downplay his relationship with Carroll, but not his enthusiasm for the electricity surrounding the game.

"Animosity, no. Erroneous, erroneous," Harbaugh said about any lingering bad feelings toward his Seattle counterpart. "It's football. It's competition. It's winning."

Former NFL quarterback Harbaugh said his team was excited about the challenge.

"This kind of game, I was thinking of the things I would trade to be able to compete as a player," he said. "I was thinking like a body part. Could I do without an arm?"

The Niners have been preparing to deal with the noise factor.

"You've got to be able to communicate without being able to hear very well," Harbaugh said. "You can simulate that somewhat in practice. Signals, hand signals, verbal signals, body language, reading lips, different ways."

San Francisco (12-4 in the regular season) split their two games this season against the Seahawks, but have been blown out in their last two games in Seattle by an aggregate 71-16.

Niners center Jonathan Goodwin said the solution was simple. "He just has to be louder," Goodwin said about signal caller Kaepernick. "There's really no special tricks."

POISE FACTOR

Poise rather than noise could make a key difference according to one Seahawks player, who said the team that loses composure could suffer damaging penalties in the ratcheted up emotion of their NFC title clash.

"It just comes down to poise," Seahawks tight end Zach Miller told reporters.

"You have to understand the situation and keep your emotions in check. You want to play with fire and passion, but when the whistle blows you have to shut it down - no matter what happens."

The Seahawks, whose defense ranked No. 1 in the NFL in both fewest points and yards allowed, have been virtually unbeatable at home, winning 16 of their last 17 games in Seattle.

Seattle's offense has relied heavily on running back Marshawn "The Beast" Lynch in recent weeks. Wilson threw for only 103 yards in the Seahawks' 23-15 win over the New Orleans Saints in the last playoff round and is facing the league's third-ranked team in points allowed.

Big play receiver Percy Harvin was still not cleared to practice with Seattle on Thursday after suffering a concussion last Saturday against New Orleans.

While San Francisco has a more dangerous crew of receivers for Kaepernick with the return of Michael Crabtree to join Anquan Boldin and tight end Vernon Davis, the Seahawks take a back seat to no one on defense.

Seattle led the NFL with a plus-20 mark in turnover differential thanks in part to a suffocating defensive secondary led by cornerback Richard Sherman and safetyEarl Thomas.

"There is no love lost, there is no love found," Sherman said about the Seahawks' feelings about the 49ers.

"That's how I'd characterize it. It's going to be intense. It's going to be physical. I don't know if there are going to be handshakes after this one."