Raising the Differential

Well I am just about finished with the front and rear suspension modifications and I am not real happy with rear suspension. I raised the rear diff crossmember by removing the rubber bushings and welding in steel plates. I also modified the front diff mount to keep the rubber bushing. Problem is when I set the car down on the wheels and set ride height my halfshafts are about 1/2" higher at the wheel than the diff. Not ideal for the toe curve.

Has anyone else had this problem and have to raise the diff more than 3/4"??

Front Diff Bracket Modify

Crossmember modify
Rear Assembly
Ride Height

You can raise the diff to whatever height you need, maybe you'll need to notch the cross member. Anyway, all you need to watch is your drive shaft angle.

Also, you may want to raise the trailing arm pivot point when you drastically raise the differential, otherwise the arm will be pointing down from the wheel to the front and your car will be much more prone to squatting. There isn't much anti squat you cang et with an IRS because the torque reaction is in the diff and it's solidly hung, however there's no reason why you should introduce pro squat in the suspension.

Thanks for the input TT. I will have to look into that front pivot bolt this winter.

Took the car for a quick drive last night. Everything seemed OK except a squeak coming from the drivers side rear wheel. I think it is coming from the T/A toe spacers in front. Other than that, no bad vibrations or anything else up to 60MPH.:yahoo:

The car looks really good

I really like those wheels

What sizes are you running and what spacers?

Yellow73SB said:

The car looks really good

I really like those wheels

What sizes are you running and what spacers?

Click to expand...

It turned out pretty close to what I wanted - Cheap set of wheels that look decent. (~$600 for all for wheels shipped)

Wheels are replica C6 Z06. I could only find one company that had these wheels in all black in the sizes I wanted. Everyone else had machined lips, different colors, etc.

Front: 17 X 9.5 w/ 255/45/17 Kumho MX's. I am using a 2.0" spacer, but I had to clearance my upper SPC arms and the lower bumpsteer blocks.

Rear: 18 X 10.5 w/ 295/35/18 Kumho MX's. I am using a 2.0" spacer, and it sticks out of the rear fender a little more than I would like. I am going to try and notch the frame a little over the winter to move the tire in a little.

Once I get the car ready to do some track days (rollbar, etc) I plan on getting a set of the CCW "Classic" wheels with the black anodized centers. That is probably a couple of years off though.

Damn,
You guys are a wealth of info. I am looking to move my body back app. 1/2", and to the left at the rear 1/4". Move the rear housing back 1" and up 1", shorten my trailing arms or go to a 5 link with shortened links. Coil overs on the rear or dual mounted composite spring.

I also have a Mustang II front that I will up grade and move forward maybe 1/8". I also hope to move my engine back, uhm 1/2" minus. Don't ask me why, cause I can I guess. No I want to lengthen my wheelbase and lower the Cobra.

Thanks Guys for a top notch site!