I have a camaro clip on my 1951 3100- the rear is obviously going to be closer now to the frame- How much clearance do I need from the top of the axle to the bottom of the frame rails? If I need to modify the frame rail- what is a way to do this?? I have about 5" now- and am going to use coil-overs with ladder bars (street truck- I hope this will make for a nice ride).