Antihero is correct. I was meaning that you should throw away the head bolts you have and buy a new set of OEM head bolts (~$75 IIRC).
I did once re-use the head bolts when I had no idea they were torque to yield bolts. It was because of a oil leak from the head gasket on a rebuild someone else did. No idea how they managed to mess up but I re-used the stock bolts without issue. But I only had that engine for 5-8 thousand kms. No idea if it would have lasted or caused future issues (ended up getting rebuilt again from a cracked ring land). It's not worth the stress to cheap out.