Hi Carlos,
I believe you are talking about the following transceiver:
10326 - 40Gb, QSFP+ Parallel Single Mode (PSM), MPO connector, 10km SMF
If so i think you should leave the QSFP+ port partitioned to 4x10GbE.
Also you will need to run a minimum of 8.41.01 to support that in firmware
Hope this helps
Best Regards
Glyn