[Formula413]

Not original or cheap exactly, but a second or third generation small block would do wonders for your FE. My Firebird has an LT1 (second generation) that makes over 300 hp and still gets 23 mpg when driven mainly on the highway in a 3500 pound car. The LS1 (third generation) can do even better. The easier stuff has already been mentioned, good tune, taller gears etc.