What is the normal time of labor for an installation of 5100s? I went to a 4x4 shop today and they quoted me $300 labor for the 5100 installation up front and the 1.5" blocks on the back. That seems a little steep to me but maybe I just underestimated the labor cost of this. I have a friend who is a mechanic that could probably do this easy but he doesnt have one of those big wall compressors. Is that big wall compressor necessary to achieve the top notch of the 5100?