Though I don't know the specific torque ft/lbs. that you'd have to get those bolts down to... before my rebuild, I was running a set of Hooker Unequal Length Headers. Now, I tell you, no matter how much I attempted to torque those things down to spec, they'd always get pushed back out over time.

I would recommend picking up a set of ARP Header Bolts, some Thread Locker (Highest Temperature Rating), and a set of Copper Head Gaskets. Place all of those in and torque them down. It should fix the problem of your bolts backing out.

-YB