The only speakers I would swap the fronts for with factory amplification are these
https://www.crutchfield.com/p_151OE692/PowerBass-OE-692T.html?tp=105
Anything with higher impedance will decrease effective wattage and volume. Making the dash speakers even more overpowering.
One of the guys on here has sat an ohm meter on the speakers and if memory serves me right dash is 3.4ish front doors are 2 and rears are 4. Which is why the rears don’t exist on the soundstage.
Try playing with the fade. Set the fade to almost where the seat cushion meets the seat back on the “overlay” on the screen. Will make a big difference.
They also make 2ohm 6.5” three ways that would “fit” in the rear. But crutchfield doesn’t explicitly list them as compatible with our trucks. Even a proper 2-3 way 4 ohm 6.5 would be upgrade over the puny speakers that exist back there. Just be careful not to go bonkers with huge magnet high wattage drivers that like crutchfield said, would be so underpowered it would be setting money on fire.
It’s a phone call I haven’t gotten around yet to making. As the audio situation is still a work in progress for me.