I swapped the rear axle in my 98 for a disc brake rear axle out of an 01.. 1 thing stands out to me, the rear rotors are significantly larger than my front rotors. i figured id just get some rotors from an 01 for the front thinking they would be bigger than my 98.. well i looked at my dads all stock 01 supercrew and his truck stock is setup the way my truck is now with the axle swap...

so my question, why are the rear rotors bigger than the front rotors???

 

i never noticed the rears being any larger diameter then the fronts, but i know the rears are solid rotors (non vented veins) so maybe they are larger to absorb more heat and apply more stopping power

 

you are correct

 

I would guess that they are bigger so there's room for the parking brake shoes.

 

x2

If you look hard, you'll notice that the braking surface is narrower on the rear rotor, but the surface that the bolt holes are on has a larger radius than the front rotors.