Ok I feel like a horses pitute asking this. What kind of MPG you turning on a relativly stock 87 up Fuel injected 454? I'm shopping for a Burb I was hoping to find a 90 or 91 with a 4l80 OD tranny but not that common. It will be a pull truck for a Airstream camper a couple weeks a year. Running into a lot of TH400 trucks. I know the TH400 is near bullitt proof so not out of the question. THis pig will be my DD so It has to get like 15mpg or better on hwy at 75 mph (We fly in GA and I'll still be getting passed often at that speed LOL).