Optiplex 7070 micro CPU Fan header

I'm using a fleet of Optiplex 7070 micro's (210-ASEF) as part of a data acquisition system. Each 7070 is housed within an aluminium enclosure along with custom electronics. We are running into temperature problems with the 7070s, with them consistently above 80 degrees at ~50% load, and sometimes getting above 90 degrees. 

I am looking into resolving this with external fans mounted to existing cutouts (for passive airflow) in the aluminium enclosure (there is already a cutout for the 7070 front panel and a large cutout for exhaust airflow suitable for 2x60mm fans). However, I would like to avoid running an additional 12V supply into these enclosures (currently everything is powered off the 7070s USB lines), so am looking into splitting the CPU fan header within the 7070 to run 1 or 2 additional fans. Thereby allowing me to run them @12V and potentially at a higher power than I would be able to off the 5V USB lines.

However, I am having trouble getting information on the header used on the motherboard - it looks to me to be similar to a JST XH series but I can't be sure. Also if there is any information available on the current rating of the CPU fan header that would help selecting fans to prevent damaging the 7070.