No, All Mitsu's DOHC from the mid 80's on have been multi valve. In the 70s they had some DOHC 4s that were 2 valve engines. Even the DOHC head for the 2.6 is 4 valve and that dates back to 83.
7mm in a Japanese engine would be very odd. French yes and some in German engines and gearboxes but that is the first I have heard of in a Mits. Sure someone did not tap them to a 1/4"? I am not even sure if there is an ISO spec for 7mm, not looked and probably won't. I have seen both 6 & 8 mm in the girdle.
The MLS gaskets are closer to the bore size than composite ones. They can take the heat allowing the gasket to be tightened up to the bore. Comatec wants the bore size on some of there gaskets.