7 Metal fuel rails for engines; fuel rail assemblies, for engines, comprised of metal fuel rails for engines, metal fittings, metal spacers, metal screws, and o-rings; fuel filter assemblies comprised of fuel filters, metal filter housings, metal fittings, metal end caps, metal mounting brackets, springs, metal spacers, metal screws, and o-rings; vehicle boost/vacuum manifold assemblies comprised of metal boost/vacuum manifolds, metal fittings, and metal plugs; check valve assemblies, for fuel systems, comprised of check valves, fittings, metal springs, and o-rings; fuel regulator assemblies, for engines, comprised of metal regulator housings, metal poppets, metal spring perches, metal spring retainers, metal plugs, metal fittings, metal brackets, metal springs, diaphragms, coated metal springs, ceramic balls, metal balls, metal set screws, metal washers, and metal nuts; vehicle fuel pump systems comprised of fuel pumps, metal flanges, metal manifolds, metal extension manifolds, metal fittings, metal plugs, nylon pump retainers, copper sleeves, metal nuts, epoxy, wires to power fuel pumps, electrical connectors, insulation, o-rings, metal screws, metal dowels, fuel pre-filters, and metal c-clips