I'm getting closer to having my '70 Duster ready to race. My latest project is a roll bar. I'm using a BD Racing bar. The tubes are notched really nicely, and the main hoop fits very well. I'm planning to mount it basically in line with the rear door jamb, with the mounting plates in the footwells. The bottoms of the bars will be way off the center of the mounting plates, but I don't want the bar to be too far forward. I figure I'll just tack weld the plates as far up into the corners as I can, then beat them flat prior to welding them in place. The base of the bar will still be fully on the plate, just not centered. Hopefully that will be OK with the Tech inspectors.javascript:void(0)

My bigger issue is the braces. I think the rear braces need to be attached to the top of the hoop, but if I do that without shortening the bars substantially, I'll have to do some cutting at the package tray. Is that what I'm supposed to do? The bars are very long, reaching well into the trunk. I'm guessing I need to cut them shorter than they are, but I don't know what the best mounting points would be. I have the same question about the front brace. Where is the best place to put the mount plates? Does anyone have pictures of where they mounted their braces?

I've never installed a bar before, and any advice would be greatly appreciated! I have attached a few pictures.

Here's another.

And another.

When I origionally had the roll cage put in my dart the guy run the rear down bars thru the speaker holes and didn't have to cut anything, I have since backhalfed it and changed it and run them to the top of the frame and cut them to just clear the bottom of the tin going across the bottom of the package tray with a small notch.

little better pic I think.

Yes.. the rear braces should be welded to the top of the hoop. It's seems that most of the cage kits don't supply long enough forward and rear bars. Even on 12 point kits, often the A-pillar bars aren't bent correct.
probably so they'll fit a Nova too.
Unless your using coil-overs, IMO.. run the rear bars as far back as possible. I like them welded over the rear spring hangers to be used as a faukum point....

http://en.wikipedia.org/wiki/Lever

besides chassis strength

I was only able to use about 1/2 of the 12pt kit and had to have new bars bent, besides buying more straight tubing

Attach the rear mounting points to the top of the shock
cross member on the frame rails... yes they should
be attached to the top of the main hoop... if they
are long enough you can have them bent and run through
the speaker holes or run them under the shelf like
Bill shows there

Before we all forget... Get yourself a NHRA rule book. It also would be a good idea to pick up a SFI chassis book if you know how fast your going or want to go later on.

http://www.sfifoundation.com/

I don't think the guy doing the cert would be happy about the bar hanging off the edge of the plate. At least he shouldn't be. Bend or roll the plate so it follows the vertical part of the floorpan up an inch or two. The tube doesn't need to be dead center but it needs to have some edge distance.

I think this is what Mr. P Body is refering to.

and this is the finished product. I wanted my cage to fit as tight as possible also, but giving up some space in this area is unusable space anyway, so make it easier on yourself.

Make sure the main hoop is as close to your body when sitting in the seat as the rule book says( I think it is no more than six inches behind you ) and the main hoop cross bar(shoulder harness attaches to it) is located properly in relation to you sitting in the seat, it should be no lower than four inches under your shoulders with you sitting in the seat and no higher than above your shoulders Don't forget about your helmet when sitting in the seat, the main hoop has to be above the top of your helmet also I don't like running the rear bars all the way back into the trunk I like using the X bar to the top of the rear sub frame kickup at the front edge of just like shown in the one picture showing the rear X brace bars

read your rule book because they are very specific head and roll bar placement
would hate to see you have to cut it out. i know i was worried to death the first time
i had mine inspected. i ran my rear tubes through speaker holes clear to the rear most
of the car.

This may seem like a lot of work but you will be happier in the end. I would take the main hoop to some one with a bender, have them bend it inwards 2" per side, just add to the existing bend at the seatback brace. Once that is done, reinstall it on the plates you have in your pics, you have the option of leaning the bar rearward, this way you can almost center the bar on the plate while still keeping the main hoop behind the B-pillar. I angle my bars 15 degrees in chassis cars but in your case maybe 5-10 degrees? Helmet must be within 6" forward of the main hoop. If your not using an X brace (recommended) then put the rear struts to the frame at the shock mounts. If it were in my shop I would use those rear struts to build an X brace and buy yourself some 1 1/4 tubing to run from the main hoop to the rear shackles. The seatback brace needs to be no lower than 4" below the shoulders, the drivers sidebar needs to pass halfway between the shoulder and the elbow while seated.