You have a chassis issue. It's not out of fuel. It's loading and unloading the rear tires.
i had this suspension setting from many years .. Caltracs, Dana 60,monoleaf ..i have onky swap the engibe from 496 to 572 .. same transmission same axle ... same tires only change Engine .. the only difference is the weight .. 572 weight is 80 lb more than 440 block .. i think ..you think this can cause unloading rear tires?
