So I recently purchased a 2007 NNBS and will be lowering it with a 4/7 drop. I was looking at the frame today and noticed its closed and not open on the back side. so my question is how does that work with the c notch, all the designs I've seen are for the open frames.

 

What do you mean closed got a pic? If by closed then you mean tube like then it would work the same.

 

yeah its like a tube, so I couldn't get the one one with the plate that has the studs....just bolts?

 

Go to belltechs website. You can view the install instructions of their c-notch. It's 2 pieces

 

you may have gotten an answer, but just in case, maybe i can answer it more directly... once you cut the notch in the frame, you will be able to slide the stud plate into the frame... I have a 2013... and the kit for my truck (I used a McGaughys 34045, as i also installed their air bag kit, but may be similar to any of the others) was for 07-13, you can see the plates in the bottom left on pic...


once the notch was cut, i slid the plate into the frame through the newly formed opening

 

the back side of the frame, has no plate etc and care should be taken if you do not want a large gap between the notch/kit and the existing frame... this, if fit up properly, can also be welded together, on the back side, remaining boxed... hope that makes sense... if gap is too large between your cut and the notch kit and you wanted to weld/box it back up, you would just make a plate for the back... it also has two plates that bolt the bottom of the notch kit to the bottom of the frame (one on both ends of the notch). took a little patience etc, while i was installing it, but if you are used to this type of work, its no big deal.

it pretty much bolts on the same way it does on an open style frame (which is why you need to be careful with notching it, if you dont want a gap between the frame and the kit, on the inside of the frame)