Jtooit is right - 28 is where they shift from oral to written retell.
DRA is decent for a child whose skills develop relatively sychronously.
My rule of thumb is to not to complain if the levels are within 10 or what I think is appropriate (1 grade level). There are enough good stories in the 30s that the kid should be fine. A good teacher will instruct many of these comprehension skills at all these levels. There's always reading at home to round things out.
We've found WJIII grade equivalents to not correlate with DRA, particularly for my asychronous kids.
