I just went through this with Cometic. You have to back off each bolt or nut and retorque it. Make a mark on the bolt head and I’d bet you get another 1/4 turn out of it. You can’t just hit them with the torque wrench. You have to back them off first.
And some of this is relative to materials used. At my age I have lived through reuse OEM head bolts and and the one use head bolts. The one use... once its stretched, it continues to stretch. Thus, one use.
I like to think quality hardware like ARP studs are capable of retorque. ARP might recommend new nuts to retorque on the same studs. I really dont know. What I do know is the difference in todays raw materials used to make hardware or anything else. So the gasket construction may be the issue or the hardware used to attach aftermarket heads may be the issue. good luck
