I currently Tank as blood with the following spec

http://www.wowhead.com/?talent=jcEGqh0Isb0zuuZhxbzhZMg

On the few single tank fights that come up, im sometimes going into dps-mode... what i was wondering tho is what i can do to max my Tank-style dps? (w/o respeccing ofc)

Should i be using diseases or is it a waste of time? Should i be in blood or unholy presence to dps?

Ive been using diseases and running blood presence, and ive got... 3/5 t7 for dps (i think) and i seem to be often capping on rp.
Ive also been using both the bloodstrike(Heartstrike) and the OB glyphs, but overall my dps seems kinda low, sitting around 2k in dps gear even with full raid buffs.

Id be grateful for any help.