These densities are correct. Some people might recommend setting the ink limits as high as possible. I disagree with that to some extent. There is really nothing to be gained from having a max as high as 2.6. Personally, I usually set the ink limit and black boost to produce a final density of 2.4. That is denser than any gelatin silver print, and produces an inkjet print with very rich blacks while maintaining shadow separation.
Here is an idea of my starting point for glossy papers (this is canson platine) with my P800. From here you can start adding small amounts of color inks for toning partitions to neutralize some of the warm green of the K3 inks.
# QuadToneRIP curve descriptor file
#
# for ultrachrome k3 inks
PRINTER=QuadP800
GRAPH_CURVE=YES
N_OF_INKS=8
DEFAULT_INK_LIMIT=0
LIMIT_K=55
BOOST_K=
LIMIT_C=0
LIMIT_M=0
LIMIT_Y=0
LIMIT_LC=0
LIMIT_LM=0
LIMIT_LK=55
LIMIT_LLK=55
# Gray Partitioning Information
N_OF_GRAY_PARTS=3
GRAY_INK_1=K
GRAY_VAL_1=100
GRAY_INK_2=LK
GRAY_VAL_2=35.8539
GRAY_INK_3=LLK
GRAY_VAL_3=10.7516
# Gray Curve Information
GRAY_HIGHLIGHT=8
GRAY_SHADOW=24
GRAY_GAMMA=1.2
GRAY_CURVE=
------
Hope that helps,
Richard Boutwell