Yes, they are aftermarket bolts sourced from ARP for Carpenter Racing. They are a custom offering in length for certain... I cannot speculate on the alloy, other than it is a chromoly alloy of some sort... given the research involved I wouldn't try an off the shelf item as a substitute for the bolts directly from them.
I called and got the numbers; I'll post them here as a reference.
3-step torque in factory sequence:
1) 20ft/lb
2) 40 ft/lb
3) 65 ft/lb