vehicle pull to the right

I just bought a 2000 Sienna with 78,000 miles. $9600 on a Honda car lot. Feel like I got too good of a deal. However, everything runs smooth. The only thing I don't like is that it pulls to the right. I read in the book Lemon-Aid under secret warranty/service tips that this has been a problem on 1997 to 2000 sienna's. Should I take it to the dealer or just take it somewhere to have alignment checked?

I have a 2000 Sienna. My only complaint with the vehicle is the pulling. Despite several alignments I run through front tires every 20K miles or less despite rotations every 3K with an oil change. Last time I put new tires on I replaced all 4 with a larger tire. The manual notes two sizes of tires that can be used. I bought the large size and have not had the pulling problem since. Ride is a lot smoother as well. Especially over 70 mph. Previoiusly it did not feel stable over 65-70 mph. Now it rides like a dream. Gas milage is worse though. I bought Michelin tires as they were top rated for that size by consumer reports at that time. It has been over 35K and the tires are wearing evenly and slowly.

what size tires? Our 99 Sienna pulls to the right all of the time and we can't keep the tires inflated...new or old tires doesn't matter. help! Karen