The Jags head into the top-of-the-table meeting aiming to record their second win of the campaign over Jim Jefferies' side and reclaim pole position in the race for promotion.
Just one goal separates the teams at the head of the standings and, having seen his side strike 24 times on home soil already this season, McNamara is anticipating an eye-catching 90 minutes.
He said: "We won't change our approach. We are at home and we have a good record here. I am confident in the guys wherever we are, home or away. At Firhill, we have scored a lot of goals, conceded very few and won every game, so hopefully we can keep that going.
"Dunfermline will come here with a bit of confidence and I am sure it will be a good game. Hopefully there will be a big attendance as well. We would like to get a big crowd in to cheer us on.
"It should be a good game, I think Dunfermline will come and have a go and that should suit us. Hopefully they won't sit in against us like Falkirk did recently. It will be an entertaining game."
While Thistle head into the Firhill clash in high spirits, McNamara does not have his problems to seek on the selection front after losing Stuart Bannigan and Sean Welsh to ankle injuries and Steven Craig to suspension in recent weeks.
Bannigan is making promising progress as he continues to recover from ligament damage sustained against Falkirk, while Welsh remains a serious concern after being crocked in training ahead of last weekend's William Hill Scottish Cup win over Cove Rangers.
Craig will spend the next two games in the stand after being sent off against the Highlanders, and McNamara admits his squad's depth is starting to shine through.
He said: "I said at the start of the season that it was important for us to have a squad of 18, 19 players, because you are going to need them over the course of the season.
"With us playing Dunfermline and looking to go top of the table tomorrow, we would have liked to have had everyone available. It is disappointing to lose Steven Craig and Welshy, and we will see how Bannigan is.
"You will get injuries and suspensions throughout the season. We have a good squad and it can be frustrating for players when they are not in the team because they have to wait for their chance to get back in.
"That is why we have a good squad. We have lost Steven to suspension, Stuart and Sean through injury and Hugh Murray was out through illness last Saturday as well.
"But we have players who can come in and do well.
"We have had our share of injuries and suspensions so far. Last Saturday was a test for us because there were a few things happening in the squad, but we have come through it well."
As part of their Remembrance Sunday commemorations, Thistle will give members of the Armed Forces free access to Firhill for the Pars clash.
It will also see the return of their traditional colours, and McNamara is keen to make it a day to remember.
"We have got the red and yellow strips back as well, so hopefully we can get off to a winning start with them," he said.
"The start has not been down to the strip, it is down to the boys in them and how they perform and how they handle the pressure.
"We have lost one game, away to Morton, and won at Dunfermline. The outcome of the season is not going to hinge on these games alone. It would be nice to win and get back top, though."