The Spectra Extra-Capacity Gas Tank is desighed to hold twice the capacity of original-equipment tank (38-gal. vs. 19-gal.) for twice the driving range. It replaces behind-rear-axle tank except on 1980-1989 pickups with dual exhaust which can also replace main tank. It's crafted from heavy-duty steel is nickel/tin plated inside and out for complete rust resistance and the electrically welded seams are reinforced for greater strength. Each fuel tank is individually pressure tested for leaks and installs easily. Won't affect ground clearance, but spare tire must be relocated. This fuel tank comes with tank, lock ring, rubber O-ring, spacers, bolts (to extend original-equipment straps), instructions and adapter kit (to modify and remount existing sending unit). Note: Fuel gauge will remain on \"Full\" longer because of increased tank depth. Not for diesel fuel.