probably not the best choice at 12 to 1 - I used to run a similar gasket back in the late 80's using Permatex copper coat spray on them - they usually would blow between cylinders after awhile - those gaskets do not have a fire ring so should not mar the head. the factory used steel shim gaskets and they seemed to last - it all depends on the how flat the deck is. The better choice would have been a felpro 1009.