Sounds like they are bought already. I concur with Pat about determining spine. If you don't have a proper spine tester, you can simply measure how much a 2 lb weight deflects the center of the shaft when placed between 26" centers. If they are too soft, you might look to exchanging them for stiffer. Spine measured this way is called the static spine, and it gets you in the ballpark for the "typical" setup.
There is dynamic spine to consider also. The dynamic spine required is affected by length of arrow, weight of point, width of bow handle and other factors. These are adjustments you make to tune the arrow to your bow, so there are some ways to make adjustments, if the shafts are not too weak and cannot be exchanged.