Mopar Electronic Pickup Polarity and Rotor Phase

8.5 mpg is horrid, but insure you are measuring it accurately. Use gas station fuel pump readings (fill-up to fill-up) and mileage markers (or GPS), not the tics on the dash fuel gage and odometer. I carefully recorded mileage in my 1969 Dart w/ slant-six in the 1980-90's and consistently got 22 mpg highway, back when the national speed limit was 55 mph and before 10% ethanol. At 75 mph, expect 30% poorer. If truly that bad, it may be running rich to put raw gas on the cylinder walls, which is why engines used to wear out faster in the day.

Understood, I do try to keep measurement methods accurate. I guess "horrible" is a relative term, it is after all a 3/4-ton truck and has 33" tires with fairly aggressive all-terrain tread pattern. Based on what most people over at Ramchargercentral tend to get on their old Dodge trucks though I think it should be more like 12-14 MPG. I know it also doesn't help I have a hard time keeping it below 70 mph on the freeway, need to work on being patient lol...