From the photo it looks like you have a groove machined to receive a loc-wire. However, it is really hard to tell from the photo. Look at the head, and if it has a ring inserted into the groove and protruding out about .010" than they are o-ringed. If you just have a receiving groove than they're set-up for loc-wire gaskets most likley.
This is a pic of my head. It is o-ringed and has the ring there, but you can't really tell by the photo whether it does or not either that well...
