I strongly remflex gaskets they are about 1/4" thick and crush down when the header studs/bolts are tightened. I have them on my Camero and Firebird and they are great. See
www.remflex.com.
Torque? couldn't get torque wrench on several fastners so I just tighted with a wrench tight drove for bit and check the tightness, never had a problem or any leaks. I highly recommend them!