looking for reasonable front brake upgrade.

Hello guys

Now that Im finally getting the 440 into my 74 Dart, Im also looking into upgrading the front brakes.

Are there any cheap swap option instead of getting a complete willwood setup right away ??

Are 4 piston Kelsey Hayes calipers interchangeble ?? Can I use these on my excisting brake rotors and knuckels ?

Hope to get some pointers and maybe some tips and tricks on the how to.

gr Arnoud