Installing custom rear frame rails in 77 Firebird Trans Am (2nd gen fbody)

[Schroeder]

I'm working on cutting out the rear frame rails in my 77 Trans am because I'm putting in DSE mini tubs, subframe connectors, and a quadralink. I am making my my own rails from 2 x 3 x 11ga (.120") walled tubing. I know there are some people that make the rails like comp engineering and chris alston, but the rails require heavy modification to the rear of the car in the trunk etc (comp engineering) or are too expensive (chris alston).

So all that aside, I'm fabbing my own up, but was wondering what I was gonna do with the torque boxes. The DSE quadralink relies on the boxes for mounting, but they're part of the rails I planned on cutting completely out. Also, They're not really that thick. I planned on following the alston rear clip removal instructions at least to get my rails out, but I'm wondering how I should maintain the portions of the rear clip that I will need to locate off for the quadralink installation. I thought about cutting around them when I cut the frame out and leaving them hang from the trunk floor pan and finish removing those parts when I got the quadralink mounted in position.

Here are the alston instructions: https://www.cachassisworks.com/Attac...915840-F20.pdf

Here are the DSE quadralink instructions: http://www.detroitspeed.com/images/i...Quadralink.pdf

Here is the link for the mini tub install: http://www.detroitspeed.com/images/i...eep%20Tubs.pdf

Here is the link for the DSE sub frame connectors install: http://www.detroitspeed.com/images/i...Connectors.pdf

What are your guy's opinions? Is it safe, better yet, is it smart to reuse the torque boxes for mounting the quadralink, or should I make my own up? The box will only be as strong as the weakest point and it doesn't look like the DSE parts that splice into the torque boxes are much thicker than the stock boxes, but I'd have verify this. Working on this now, so some quick help would be MUCH appreciated guys! Thanks in advance.

[krom]

These guys show rails for $335 a pair http://autoweldchassis.com/spec.ivnu

[Schroeder]

If u go with parallel frame rails the gas tank location will be all screwed up won't it? The fuel tank will have to get a lot more narrow, correct? I think that is the trouble with the competition engineering rails. I should call them and see how much more narrow it is to determine how much more narrow the tank will be. This is also something I should ask about the competition engineering ones to compare the 2