Zone's 4" Lift Kit on our 2005 F150 4WD
First up, our Zone 4" lift kit. The kit allows for the fitment of 35x12.50" tires on a set of 20x9" Fuel Hostage wheels with a 01mm offset without any rubbing. The kit uses strut spacers up front and a larger rear block with U-bolts in the rear to generate the lift. The kit also included lifted knuckles, differential drop brackets, dropped crossmembers, a differential skid plate, lifted knuckles, new rear shocks, new braided brake lines, e-brake cable drop bracket, and all the hardware you need to get the kit installed. The kit is extremely straightforward and comes in at a great price point.
Zone's 6" Lift Kit on our 2007 F150 4WD XLT Project Truck
Now the Zone 6" Lift Kit. With this kit on our truck, we managed to squeeze on 20x10" Fuel Lethal Wheels with a -24mm offset with Mickey Thompson Deegan 38 35x12.50" tires, and only had a slight rub near on the front valance at close to full lock. The actual difference in hardware between the two kits is almost nonexistent. In fact, the only hardware difference between the two is that the 6" kit comes with taller front strut spacers and a larger rear block to squeeze out the extra lift. That also means that install of both kits is remarkably similar.
So which kit should I get?
That's the burning question, isn't it? Compelling arguments can be made for both. On one hand, a 4" kit will let you fit on 35" tires and generally cost a little less. 6" kits do give you a smidge more ride height, open up a few more wheel and tire size options, and costs just about the same amount to install as a similar 4" kit. Anyway, here's some side-by-side comparisons of the two kits on trucks with the same size tires for your perusal.