2 piece ford cap will work on '57 to at least '75 or so. Make sure you get cap(top), adapter(center section) and rotor. also will need corresponding plug wires. Reason Ford went with the larger cap is so plug wires are farther apart and eliminates cross firing. Also new cap has "male" plug wire connector so that eliminates moisture collecting as on the small cap. I used this set-up on my '81 302 w/ mid '70's point dist.