Questions on C notch

[vht]

Going to C notch my frame on my 51 and have a couple of questions. I have the TCI 4 link with coil overs, TCI frt susp with 2 in dropped spindles, coil springs and reg shocks. I'm planning on mine being low, but not to the point I have problems getting up my gravel driveway. I was going to notch it 1/2 way up into the frame, finish boxing the frame and then adding 2 in with a piece of box tubing on top for strength. With that extra 2 inches, will I have to raise the bed floor any? Since I don't have a bed, I don't really know how much clearance I do have. I don't know if I need that much but since I'm boxing the frame and may want to lower it more later, I'd rather go on and do it now. Anyone have a similar set up with pics?