This engine plate can be used on NC quarter midget models that have the steel slotted engine strap brackets welded onto the frame rails. There is tolerance built into this assembly for cars and engines that have been warned down with use. So, we suggest taking a little extra time when first mounting the base plate. Utilize the top plate to get the base plate as square and toward the back of the slots as possible before fastening it tight to the steel straps. The engine should also be double checked for squareness in the car before fastening tightly to the top plate. Utilize the engine and axle gears with a small straight edge to verify the squareness of the assembly in the car.