ACC's carpet fit well in my '63 wagon.
Not a lot of room in '66-'67 rear wheel wells, but lots of guys here own them; try the Archives here if you don't get enough info on this thread. If I remember correctly, you're probably limited to 7" wide, 4.5" BS, 255 or maybe 275 wide tire as far as off-the-shelf stuff. Height-wise, the front of the wheelwell (for fronts & rears) are the traditional Mopar tight spots. Rim diameter is pretty open depending on your brakes (big disc swap?) and the car's intended appearance.