I have a 54/3100/235 with fenton headers and offy manifold, dual Rochester's and dual flowmaster 40's. i have a 2.73 nova rear end and 235/75/15 tires on rear. i get 15.5 around town and have gotten as high as 24 mpg on a long trip. my average on a trip to KC in Sept. was 17 mpg down from and average of 20 last year. i also installed E3 spark plugs and my in town mpg went up 25% to the 15.5 average. Btw i have t-5 tranny from an s10.
