"We found a new old stock OEM pair that fit the earlier 318 bores much better."
do you have a pic and a part number?
hint
you want the gasket to fit where the cylinder "sleeve" is not inside it
While I technically agree, people have used the large bore FelPro blue gaskets on 273s for decades. It's really not critical. If it was a mass problem, there would be bore specific gaskets available. It's not.
