Jeff, some gasket sets come with the metal plate to block off the heat crossover. Tried the old Coke/Beer can cut up, burned right through. The cans are too thin now days.
Couldn't find a metal block off for my engine so I found a couple in my tool box from a Chebby that worked with a little modification. Never had a problem with them...yet.
Saw these gaskets that are already blocked.
https://www.summitracing.com/parts/s...ake/oldsmobile
Kelly