Jed,
i think you should betting getting better then 10mpg with an inline 6 even if your rear gears are 4.11s my now stripped 1978 Chevy Suburban got around 8 with my reg. somewhat on the pedal and hotroadin driving but if i cruised on the highway and not alot of town driving i almost got 12 and thats with a 350 V-8 with 4 barrel 4.11 gears stock 4 spd 1:1 4th gear 4 in. lift and 32 in tires so something ain't quite right with your sixes i think but then again i don't really know either
Nate
