THE PLT REPORTED HE RAN A FUEL TANK DRY DURING FLT AT 6000 FT. HE SWITCHED FUEL TANKS, TURNED ON THE BOOST PUMP & MANIP-ULATED THE ENG CONTROLS, BUT WAS UNABLE TO RESTART THE ENG. DURING A FORCED LANDING ON I-581, THE ACFT STRUCK A PICKUP TRUCK (TRAVELING IN THE SAME DRCTN), THEN VEERED INTO AN EMBANKMENT. NONE OF THE OCCUPANTS IN THE TRUCK WERE INJURED. ANEXAM REVEALED ALL FUEL TANKS CONTAINED FUEL EXCEPT THE L MAIN TANK. THE BOOST PUMP SW WAS FND IN THE 'PRIME' POSITION, A CONDITION WHICH COULD CAUSE FLOODING OF THE ENG. DETAILS OF AIR RESTART PROCEDURE & BOOST PUMP POSITION NOMENCLATURE DIFFER BETWEEN MANUALS/ACFT MARKINGS. FUEL MANAGEMENT FOR THE 4 TANKS REQUIRED POSITIONING 2 SELECTOR VALVES THRU 6 POSSIBLE POSITIONS. TWO FUEL GAGES WERE INSTALLED; 1 WAS FOR THE 2 MAIN TANKS, THE OTHER WAS FOR THE 2 AUX TANKS. THE GAGES INDICATED ONLY THE QUANTITY OF FUEL IN THE SELECTED TANK. THE OTHER GAGE READ EMPTY WHEN NEITHER OF ITS RESPECTIVETANKS WERE SELECTED. FLT MANUAL PROVIDED ONLY LIMITED INFO ON FUEL SYS. PLT'S FACE INJURED, NO SHOULDER HARNESS INSTLD.