This steel mid plate is designed to bolt between the engine block and the bell housing. It is thinner and made for cars with an existing production firewall. This mid plate must be used with a motor plate to complete your engine installation. It is sculpted to fit the firewall of production cars and bolts onto the frame rails by fabricating your own mounts. Material is .100"-thick steel and is laser cut to fit Chrysler 383, 426, or 440 engines. Use part number 6036 bracket set for easier installation.