I see that another nice project is coming, good luck!
SGII and a grill block is a great start, along with pumping up the tires and thinner oil it should give you noticeable difference in FE. But if you drive mostly in suburbs and city it good to think of loosing some weight. Maybe a smaller battery, maybe some junk from the trunk? Unused seats and carpets?
Anyway keep us posted on the progress.
