340 stroker 422

Given the location. And their 98 ron is similar to 93 in the US right?
If no option for parts swaps. I would run the numbers on 106 and 108 installed centerline with that cam and a .050” gasket (still utilize quench properties). Double check all the measurements to be sure on compression. But 11.8 sounds right with a stroker and flat top piston right?