I don't use SAS.... it is my understanding that most who did have moved on to SSDs.
Here is the most recent version of your service manual.... there will be no more coming:
http://h20628.www2.hp.com/km-ext/kmcsdirect/emr_na-c01715080-8.pdf
Here is an interesting HP document:
http://h20564.www2.hp.com/hpsc/doc/public/display?docId=mmr_kc-0100529
That is not what you are asking about, but it may give you some clues. Perhaps the "Blind Mate" connector the drive slides into accepts both SATA and SAS drives (without the gray adapter needed?). Your SAS drive is a 3.5" form factor. There are posts in here on our favorite 2.5" to 3.5" form factor adapters to use with the Blind Mate system in these workstations (but that would not be an issue for you with your 3.5" drive).
The cables coming out from the Blind Mate receiver go down to the motherboard SATA port set (the upper set). Those can be shifted to the lower set of ports. Personally I'd move on to SATA SSDs, or a single SATA SSD and a nice 2TB HP HDD off eBay (SATA II or III if it is HP; SATAII if it is not HP).
Read up on the recommendations by HP that if you are going to use a SATA generation 3 drive in one of the HP SATA generation 2 workstations (which yours is) then you should use a HP branded SATA gen 3 drive. Personally I use Intel 320 series 300GB SSDs bought used off eBay.... they are SATA gen 2 drives and we have about 50 running this way. You can experiment with non-HP gen 3 SATA drives, but I figured I'd not risk that. Even the 160GB 320 series one would be great for you to experiment with at a very low cost off eBay. Virtually all I have bought this way have 100% life left when probed with the free Intel ToolBox software.