1959 Coupe Header question

[Rocket455]

Title states 1959. I meant 1950. Sorry. This is a shoebox question.


What is the difference between a convertible car and the rest that make some headers only fit convertibles? What is in the way?


And for a convertible it's less than half the price. You'd think they sell more non convertible ones so they'd be cheaper. what gives?


Fits non convertible only $350
https://www.ecklers.com/1949-51-ford...9-19585-1.html


And for convertible $128.
https://www.ecklers.com/1949-51-ford...9-19584-1.html