Your art-board in Illustrator should remain at 5 x 7 to represent the extent of the finished cropped page. But do allow the design to overflow from those extents to create the bleed.
In this simple example the screen grab from Illustrator shows I have an art-board of 5 x 7, seen as the black rectangle with the design overflowing it.
The rulers show that the actual document is about 8" wide to accommodate the bleed and crop marks. But the crop marks indicate that the actual page edges are 7 x 5 as defined by the art-board size in Illustrator.