I have these Gaskets used on several Magnum engines and I have to say they hold up very well and seal much better than the thinner options. Attention, handle it very carefully, you can damage it very badly by bending it.
Pros
Remflex exhaust gaskets come standard 1/8" thick and are rated for 50 percent failure so they can fill any hole or gap in the flange face up to 1/16"