Adjusting cook time/Oven temp for dressing?

[swfood]

I am planning on roasting turkey at 325 and plan to place the dressing (in a casserole dish) in the oven while the turkey is roasting.

The dressing recipe calls for 350. How much extra time should I allow b/c the oven temp is slightly lower then what is called for in the recipe. Is the 25 degrees negligible?

[chefj]

not much more. An extra 20 min I would think.