Installing a Custom Rear Frame Brace

First and foremost, I would like to point out that this modification applies to the F-bodies with rear shoulder belts only. I.m sure it can be done with out them, but my instructions are for those so equipped. Also, I can not guarantee any performance gains with this mod. In my case, with a 90 Formula, I have in fact noticed a more rigid rear with a lot less flex up top. First things first.

Tools Needed
Hacksaw
Dremel with Reinforced Metal cutting tip/disk
Heavy Pliers
Drill with various Bit sizes (not sure which size mine was)
Ratchet Set with extension

Parts Needed
(1) 1-1/4. X 1-1/4. 6ft. Steel Girder
(2) New Metric Nuts (M12 1.75)
(2) Same Size Lock Washers

I will start by assuming that the back seats are already removed. If so, then the shoulder belt mechanism will need to be removed. To do so, pop off the plastic cover, then simply use the ratchet w/ extension to remove the big bolt. It should slide right off after that. So as of now, the bolts should be in plain view. I went to Lowe.s to get my steel girder, I.m sure Home Depot would have them, and if you.re lucky, your local shop might have them too. It was about $13 or $14. I got a 1-1/4. by 1-1/4. by 6ft., but a 1. by 1. will do, it might require more work though. I then brought one of the factory nuts with me so I could purchase 2 new ones without the flange on them (flange interfered with space). I picked up 2 matching lock washers so they won.t slip off. Then I measured the distance between the 2 bolts and allowed for some overhang, and it came to 55.. I cut the girder at 55. with a hacksaw and smoothed the edge with the dremel. The exposed thread was not long enough to allow 1-1/4. on top of the nut, so I had to dremel out corners about 2. deep. If you hold the girder up to your eye as if you are looking down it like a periscope, you will need to cut two of the four corners about 2. deep into the girder. After that, you should be able to .peel. that cut piece up with some heavy pliers. Dremel that piece off, and you should be left with a girder that has only three sides as of 2. from the end. Repeat for the other side. Now, place the girder on top of the bolts with the missing sides facing up at the sky. Mark off the spot you will be drilling with a Sharpie or other marker. For a better accuracy, you can measure the distance it will be and get an exact drill spot. Next you will need to drill the holes.I am not sure what size bit I used, but you can easily tell by holding it up to the bolt and seeing how thick you will need. Once you drill it out, test to see if it fits, then bolt it up!

This mod can be done a number of ways. This is the way I saw right off the bat. All you really need is a girder, no back seats and a good supply of tools and you can do it what ever way you see fit. Also, I am currently working on a way to brace the cut part of the girder for an even better brace. I will let you all know when I am done with that. Sorry for the lack of pics, but if you have any in depth questions, drop me an email at Treview1@hotmail.com.

Good Luck!