C notch or not

[vht]

My 51 has the TCI mus 2 front susp, and rear 4 link with coil overs. 2 in drop front spindles also. None of this is installed yet since I'm working on the truck. I'm going to box the frame and I was wondering how much of a notch I'll need over the rear end. I've got some 2x2, 1/4 in wall that I was thinking about making it out of instead of doing the regular cut in the frame. I would think this would be stronger. I was going to weld it up, notch where it goes in the frame, weld it in and then cut out the portion of the frame. I don't know how much clearance I really need. The 4 link brackets are installed on the frame already so I thought I could install the bars and rear brackets and find out where I need to be.