SCBondsman, welcome to TFL.
CaCrusin hasn't visited TFL since 2007, so you're probably going to have a long wait for a response....
You'll likely do better to ask this question of someone at Blackhawk, via the
contact page on their web site. Then again, you may not need to ask. The
SpecOps Stock page has a bunch of accessories at the bottom, including a 3-point sling....