THE PILOT AND HIS DAUGHTER WERE ON A CROSS-COUNTRY FLIGHT WHEN THE ENGINE LOST POWER. DURING A FORCED LANDING APPROACH TO A HIGHWAY, THE PILOT NOTICED SOME POWERLINES WHICH HE WENT UNDER. HE AVOIDED THE POWERLINES, BUT HIT A TRUCK. THE CRASH SITE WAS LOCATED WITHIN 5 MILES OF THE DESTINATION. THE PILOT WAS SERIOUSLY INJURED AND HAD NO RECOLLECTION ABOUT THE ACCIDENT. HIS DAUGHTER RELATED THAT THE ENGINE SOUNDED LIKE IT RAN OUT OF FUEL. DURING AN INVESTIGATION, FUEL WAS FOUND IN BOTH TANKS. THE RIGHT TANK HAD THE LOWEST LEVEL OF FUEL WITH 3 GALLONS REMAINING. THE FUEL SELECTOR VALVES WERE FOUND TO BE VERY STIFF AND COULD NOT BE SWITCHED TO THE LEFT TANK. THE AIRCRAFT HAD BEEN REBUILT FROM 3 OTHER PLANES AND DID NOT HAVE THE LUSCOMBE AUTHORIZED FUEL SYSTEM INSTALLED. THE ENGINE RAN NORMALLY DURING AN OPERATIONAL CHECK.