mill the snot out of the heads to get a very high comp ratio and cyl pressure (11:1-12:1) and use water injection to control detonation...I've got an article from Mother Earth News from '79 where a guy did this on a ford festiva...he had the motor running a 12.7:1 comp ratio and was averaging 50 MPG CITY (easily a 15-20 mpg city increase), while passing all NOx emission standards for the time....
1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!*** 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
