Another semi boring update...here are some pictures of my spacers I made for the 350Z brackets.
I did not take pictures of how they look in the seats (I will on next seat), but basically I welded a thick flat piece on both sides: One directly to connect to the 350Z rails, and on the other side which formed a box. The end result was a bit overkill, but more surface areas was welded to the original frame and I got some additional needed clearance for the custom mounts I am making in the car.
Pictures Taken Oct, 2015
More on my site, but meh not much to look at: http://www.doitinadatsun.com/yoak/2016/03/240z-350z-bracket-spacers/