boring the head out?!!
williams has longer stroke and slightly larger bore to give 2.0. the longer stroke and heavier crank reduces the max rpm. it also has larger inlet valves.
so...to make your F7P into 2.0, youd fit the williams pistons and crank. the block needs machined to accept the larger webs. larger valves would be beneficial, but alot of people use the 2.0 bottom with the 1.8 head.
would be easier if you could find a williams lump and chuck that in...