Rear Frame Rail Notching How To!

I did mine the same way as Don, but used the original outer skins. I haven't had any problem with the quarters buckling at all. This has allowed me to run a 9" rear with 15x10 rims on 5.5 bs, with 28x10.5 ETS's with no trouble.

With a little work and fabricating it's a simple, straight-forward job. Getting ready to do this on my 86 GN, also.

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Kevin's kit wouldn't work with Louie's 9" with the high axle housing mounting location unless there was room on the brackets to add a few holes higher than the stock location. That would also make clearance with his roll bar more of a problem.


Exactly.
 
Rear suspension is done. I have a new found respect for people that cut, fab and weld everyday. What a PITA. I found muscles that must have been on vacation for the last decade or so.

If I had to do over, I would move that roll bar higher. The uca to roll bar is very tight. I bounced the car in the back and it's not contacting. I'm going to test it again with another person helping to see if it will contact.

The stance turned out just as I hoped, and I didn't have to use spring spacers.

The rear is centered and aligned. I set the pinion angle 1 degree down from parallel with the trans output shaft.
Roll bar is set at no preload.

My car was in an accident before I purchased it, and the left front area of the frame is bent up and back. This produces about a 1/4" drop at the left front and takes a bit of weight off the right rear. I'm thinking of installing a 1/4" spacer under the left front spring or installing adjustable coil over shocks in the front. I wonder how much the left front tire is offset back? Maybe that is helping me get that 1.28 60 foot.
 
After installing the rear end and centering it left to right, the lower control arm offsetting spacers I made put the lca's on a good angle in relation to the car centerline. The uppers are clearly at unequal angles in relation to the car centerline. I'll be fabbing up some offsetting spacers for the uca rear ball joint mountings. Offsetting will be 1/4", just like the lca's.
 
After offsetting the uca rear mountings 1/4", the angles looks much better. It forced me to reset 3 control arm lengths, but it didn't take long to do that. Time to launch the mother.

If anyone is wondering what the angle difference is between the transmission shaft centerline to the trans pan rail or the trans pan, it's 5 degrees on a turbo 400. That little bit of information makes checking u-joint angles much, much easier. Just plop a magnetic protractor to the bottom of the trans pan and do the math to get your engine/trans centerline angularity in relation to ground level.
 
Here are some pics of the notching work.
 

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Very nice job on those welds on the notch... I noticed you didn't bang out the wheel wells. Did you find you didn't need to do this?
 
Very nice job on those welds on the notch... I noticed you didn't bang out the wheel wells. Did you find you didn't need to do this?
The pics were taken before I pounded out the most lower lip section of the inner fender well.

One thing to note that just came to me. The new suspension is not any more noisy than the setup I had in there before. No bangs or creeking. As far as normal driving goes, it doesn't feel a whole lot different. Granted, I didn't take it out on the street to check body roll on corner turns. Just some forward and back runs down the complex driveway.
 
By the way, the material used to cap off the notched frame is 1/4" chromoly steel flat plate tig welded into place. Expensive, and a time consuming method, but much stronger.
 
When I look at the artwork under the car, I can see where your bank account now is.:eek: Simply breath taking. You did a fabulous job. Any shots of the full car off the hoist? I would love to see stance.
 
When I look at the artwork under the car, I can see where your bank account now is.:eek: Simply breath taking. You did a fabulous job. Any shots of the full car off the hoist? I would love to see stance.
The stance is not as cool as your white T, but it should work well for the track. I'll get a pic together.
 
June 8 post (Permalink #108)...the first photo really puts the notching (cutting) of the frame in perspective. There is not much left is there? Since you have a full roll cage, you won't have a problem. However, us street guys without roll cage need to tread lightly. Someone needs to design a weld-in back half that doesn't sacrifice strength but looks stock and is strong. It will require a different fuel tank so it won't be cheap. Dreamin...dreamin!
Conrad
 
Donnie

what is the spring rate and length on those rear springs.

makes for lots of room back there!
also, does the location of the anti roll brackets on the rear axle make a difference? wider vs narrower
thanks
 
Here's a couple of pics of the stance.
 

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what is the spring rate and length on those rear springs.

makes for lots of room back there!
also, does the location of the anti roll brackets on the rear axle make a difference? wider vs narrower
thanks

The rear springs are Afco 14" x 125 lbs/in rate.

I would try to make the roll bar links at right angles to the axle housing. That way body sway won't try to push the axle housing to the side.
 
Here's a couple more. The rear tire seems pretty well spaced in the fender well.
 

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