Rear Unibody Question

Hello, I read somewhere about someone cutting the back of the body at the unibody and removeing the nutstrips and actually inserting some tube in place of the nutstrips and then building their bumper off these tubes. I was wondering if anyone could link me to the person who did this, and or let me know what the deminsions are of the inside of the unibody so I can purchase the tube before hand. This is my daily driver so I don't want to have it taken apart any longer than neccesary. Hope this question makes sense. Thanks in advance for all your help.

I'll be doin this this weekend when i build my bumper. i plan on using some 2"x4"x0.250" wall rect tubing. Keep an eye open for a build thread on it very very soon

http://naxja.org/forum/showthread.php?t=931945&page=2

This is a good build thread in general, Dan and mine are in there, we both did the same thing

Here's what I did to mine.

That was the exact thread that I was looking for. I read it some time back and that gave me the idea to make mine the way I am going to do it. Will post up when I get something going on it. My buddy is the welder and he has slowly been finding pieces of steel for me. Will let you guys know something when I start mine. Thanks again.