Dayton Parts is a broad line manufacturer of leaf springs for pickups, vans, buses, cars, trailers, medium and HD Trucks. It descended from Stanley Springs which began operation in 1922 and has grown to be the largest and broadest line of aftermarket leaf springs serving the North American market. Dayton Parts manufactures both parabolic and pyramid style leaf springs in it's large plant in Harrisburg, Pennsylvania. The line consists of OEM replacement leaf springs and Heavy duty upgrade springs, Special Extra Leaves, and Full Taper Extra Leaves for use in suspension upgrades. Complementing the springs they manufacture, Dayton sources pins, bushings, hangers, shackles, helper kits and other suspension parts from the world's top manufacturers.
| Make | Model | Years |
| Ford | Mustang II | 1974 - 1978 |
| Ford | Mustang | 1964 - 1973 |
| Mercury | Cougar | 1967 - 1973 |
