Pardon my lack of knowledge, but I am considering a lift kit for my 2010 DC. As luck would have it, I found a neighbor who installed a 3" Revtek on exactly the same truck. But what I am having a hard time understanding is that the blocks on the back are only about 1" or 1 1/2". The truck did increase in height about 3" but that was due to larger tires/wheels. So, why is it called a 3" lift kit?