1989-1996 Ford E-350 Econoline 7.3L V8 DIESEL;. 1997-1998 Ford E-350 Econoline 7.3L V8 DIESEL; With Threaded Filler Neck;. OE Equivalent Fuel Tank Cap;. Fuel Tank Cap;. Gates - Driven By Possibility. Two-way action pressure relief/vacuum relief valve allows fuel tank to ?.