The gauge is 13 sts = 4"; the rows are 16 = 4". It shouldn't be much more than 8" after 34 rows, so yes that's a bit long. I think the 6_ " is supposed to be 6½", it just didn't come out. Maybe you could measure from the end of the ribbing; as long as you do the same thing on the fronts too, it should be okay.
sue- knitting heretic