Fuel Pressure Regulator #8190 is for carburetor applications that require consistent pressure from 4. 5 to 9 psi. It features two 3/8" NPT outlets, one 3/8" NPT inlet and is adjustable from 5 to 12 psi. This regulator is manufactured from billet aluminum and features a Nylon-reinforced nitrile diaphragm for excellent heat and leak resistance. Fuel Pressure Regulator #1789 is ideal for providing consistent pressure in Edelbrock 94 or other low pressure carburetor applications. It features two 3/8" NPT outlets, one 3/8" NPT inlet and is adjustable from 1 to 4 psi. Features a chrome finish for a great look when installed.