Try one of the Ford Truck Forums, they will be a better resource for that.
Doing an active setup is a step that I would recommend you wait until you get your factory radio integration thing figured out and learn more. You can still use the Rockford DSP with the passive setup and then switch to active later by removing the passive crossover and wiring directly to your amp after you set up the DSP for active. There are many great sounding component sets that use passive crossovers. Many of the best home audio speakers use passive crossovers. Get a good quality passive component set with good mid woofers from companies like Facal, JL Audio, Illusion Audio, or Morel. You can swap the tweeter from the component set for a different tweeter with a lower resonant frequency later if you want to raise the sound stage with an active setup. It will be a lot easier to start this way and you'll be up and running more quickly too.
Take out one factory speaker and measure it or use one of the online retailers fitment guides to help there.
Unless they come combined as an active set from the manufacturer than it won't be that easy. You need to look at the Thiele/Small parameters or T/S parameters for each type of driver. For the tweeter you'll want to know the fs of the tweeter to help you figure out how low it can be crossed over to the woofer. For the woofer you'll want to know it's fs too but also Q parameters and usable frequency range so you can cross it over to the tweeter without any holes or gaps. The cone material of the woofer and the tweeter type and material give each driver a signature coloration or certain sound characteristic. All these things have tradoffs or comprise one charaterisic for another. Then there will be how each driver will behave in your vehicle, which is about the worst environment for a speaker full of compromises and much less than idea situations. It gets complicated so again this is why I say start passive and then active once you have learned more through research and these forums.
Here is some more good reads for you Bob.
https://www.eminence.com/support/understanding-loudspeaker-data/
Positioning a woofer box in a car trunk - bass cancelation - Houston TX
