Yea! Sorry I won't make the Toss too! BUT your 10 mpg is because of the bad carb....and DIST. curve! What year is it? Your diff gears are most likely 2.43s!! You can get 30 out of 455 ci is it turns slow enough! It's only pushing 3000lb! My bud, Ron R. with the 455 in the early gets over 20 on the freeway..back and forth to work..... Matt