2003 Civic Pulls left a little when full throttle.

[Jecht]

It isn't an alignment issue, all FWD cars do that. It may be that you just notice it more with the different wheels/tires.

Read this: http://en.wikipedia.org/wiki/Torque_steer

Also, you shouldn't need an alignment if all you did was put new wheels on there. If is a good idea to have the wheels properly balanced though.

When the driveshafts have different length and excessive torque is applied, the longer half shaft flexes more than the shorter one, thus causing one wheel to momentarily spin more slowly than the other, resulting in a steering effect. So the equal length of the driveshafts reduce the torque steer effect.

What this means is that larger wheels are heavier, and increase the strength that it is going to pull to the side because it makes it even harder for the longer shaft to get it moving.