If you're using TTY bolts it's 60 pounds. If you're using ARP or some other, follow their recommendation. I torque ARP to 85 pounds. Be sure to tighten them in the proper sequence.
Scroll down to the bottom: http://www.gnttype.org/techarea/misc/torque.html
That's always been my first choice. Also, in my humble opinion, if you're going to go with the bolts, do not retorque or you will compromise the thread sealant.