Copper head gaskets for Briggs Animal. World formula, Modified 206's and Billet blocks with the Briggs head bolt pattern . They are 042" thick and available in the following sizes: 2.705" 3.025 3.050" 3.070"
If you don't see your size listed you can use a die grinder to enlarge a smaller size to what you need.
You can also shape a smaller size to match your combustion chamber especially on the intake side to prevent shrouding of the intake valve.