This is a fibre gasket not metal.
Yes these are considerably better then normal exhaust gaskets for older cars and YES they are considerably more expensive. You pay for what you get in a nutshell...
Most Pontiac Heads used this gasket.. the "D port" series.. 95% did..... & these are for use on older manifolds or hedders, Ultra-Seal, Steel Core Laminate, Open Center Port - where a metal original style gasket will not take up the micro gaps that may have manifested over time.....
This "D port" normal gasket kit fits most 1967-79 PONTIAC V8, (except for a few special ROUND port early 70s performance heads).
Always use a exhaust gasket compound or silastic sealer with these.
Each set has open center square or "D" shaped ports that measure 1.53 in. x 2.00 in.