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Author Topic: 74 vette rear end/ suspension question  (Read 5146 times)

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Offline so cal racer

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74 vette rear end/ suspension question
« on: December 17, 2007, 04:44:31 AM »
I am looking at a 74 vette and need some info on rear end and suspension mod's for this car and also rear end gearing?  so cal racer
« Last Edit: December 17, 2007, 05:00:25 AM by so cal racer »

Offline SPARKY

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Re: 74 vette rear end/ suspension question
« Reply #1 on: December 18, 2007, 11:14:10 PM »
There are several vette guy's that will chime in soon
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Offline Chicane

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Re: 74 vette rear end/ suspension question
« Reply #2 on: March 01, 2008, 08:02:07 PM »
What kind of modifications are you considering?? There are simple things like a solid differential location kit that replaces the bushings with solid aluminum, spherical inserts in the rear control arms, an adjustable toe modification (uses a bolt for the adjustment, not shims) for the rear controls arms, an HD rear differential cover, heim jointed toe rods, heim jointed camber rods... etc etc... all the way to a 5 bar rear suspension... along with various spring rates and shock valving.

The front end has the typical modifications available... control arms, del-a-lum control arm bushings, spreader bar, heim jointed stay bar (sway/stabilizer bar) end links, various spring rates and shock valving... etc etc.

Gearing available:

2.73
3.08
3.23 OEM (no longer available, except good used)
3.36
3.55
3.70/3.73
3.90
4.11
4.33
4.56

There are even 12bolt internal conversions.

A couple of links to some stuff... http://www.tomsdifferentials.com/catalog.asp?pg=17 and http://www.guldstrand.com/scripts/prodList.asp

I used to work for ole Dickiepoo Guldstrand building F and Y bodies. All of his stuff can be DYI as it is pretty straight forward. Not to mention that it has been more than field tested per-say.

Offline vette#128

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Re: 74 vette rear end/ suspension question
« Reply #3 on: March 05, 2008, 05:33:04 PM »
I am looking at a 74 vette and need some info on rear end and suspension mod's for this car and also rear end gearing?  so cal racer
 

The biggest problem I had with my 85 Vette was once I began to go fast, the back end would get light, among other handling problems. Notice when you jack up your Vette, the camber changes from negative to positive? (Dodge independant rear suspension)  Not good..... when it goes positive at speed, you will spin. I lowered the strut rods so they are parallel to the half shafts..... Now there is no camber change  8-) You can make your own brackets, but I bought "Smart Struts" from Vette Brakes which have adjustable rod ends instead of the cheesy GM rubber bushings.  The other big improvement came from lowering the front end. In order to do this right you have to get rid of the transverse leaf spring (easy choice for me as it broke at over 200 mph, making for an interesting ride) and install coil-overs. I got mine from Exotic Muscle in Tempe AZ. They are a bolt-in install, and are fully adjustable. Now my front end is down in the dirt (er...salt) and due to the rake, the rear lift is diminished. I was able to take a lot of negative camber out of the alignment as a result. One thing I learned - whenever I got the car to handle well, as soon as I went 10 mph or so faster, it would get loose and I would have to adjust the alignment again, and or adjust ride height, etc.  The biggest surprise was that the more I lowered the rear, the looser the car got. Apparently C4's like a bit of angle of attack.
Ed
Ed Van Scoy
Four Deuces
(Salt,Dirt & Pavement)

Offline Stan Back

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Re: 74 vette rear end/ suspension question
« Reply #4 on: March 05, 2008, 08:42:26 PM »
Boy, there's some experience that cost you a lot of work and grief.  Now if someone can cash in on your generosity and save themselve's some.
Past Member of the San Berdoo Roadsters -- "California's Most-Exclusive Roadster Club" -- Fifty-Seven Years of Leadership  Is Enough

Offline vette#128

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Re: 74 vette rear end/ suspension question
« Reply #5 on: March 07, 2008, 10:39:40 PM »
Boy, there's some experience that cost you a lot of work and grief.  Now if someone can cash in on your generosity and save themselve's some.

Thank you. I will admit to some paying of dues here...... an intelligent person would have yanked the IRS out and avoided all the grief  :?
Ed
Ed Van Scoy
Four Deuces
(Salt,Dirt & Pavement)

Offline Chicane

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Re: 74 vette rear end/ suspension question
« Reply #6 on: March 08, 2008, 03:22:50 AM »
Well... we have run the 866 car (68 L88 Y-body) with the stock OE front and rear suspension for some 20 years... without any handling issues. Although, the spring was changed to increase the rate. The front spoiler is not currently on the car as it was removed by mother earth at speed.




One thing to note when you lower the front end... you will get to a point to where the UCA's are a little short and will not allow the necessary alignment to bring it back from having too much negative camber. The thing with this chassis is... that you have to get it in the weeds and get the underbody air flow minimized.


Offline Carl Johansson

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Re: 74 vette rear end/ suspension question
« Reply #7 on: March 09, 2008, 06:57:32 PM »
Boy, there's some experience that cost you a lot of work and grief.  Now if someone can cash in on your generosity and save themselve's some.

Thank you. I will admit to some paying of dues here...... an intelligent person would have yanked the IRS out and avoided all the grief  :?
Ed

Hey Ed,
Carl Johansson here.  I have talked with you a few times regarding my 88 -  as I recall you helped tech it at el mo last year.  So now we are going to the big horsepower motor -  so I expect we will encounter the same issues you had with the rear end suspension.  I assume just putting bump stops to stop the travel of the IR wouldn't be a good solution -  correct?  so would you recomend changing out the rear end -  like putting in a ford 9" or something similar?

Thanks for taking the time to share your knowledge and experience!

Carl Johansson
Carl Johansson
 Auberry Ca