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Rear lowering bolts?

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Old May 10, 2016 | 05:36 PM
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Default Rear lowering bolts?

Hi all, just installed new wheels, 17/18 staggered setup and would really like to drop my rear a little. After searching here on the forum I found someone that used 11.2" M14 Grade 10.9 bolts from Fastenal and I wanted to see what other size bolts work as well for a 1-1.5" drop. Also, do I necessarily need to drop the front....heard it's a pain. Thanks for all your help!
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Old May 10, 2016 | 05:46 PM
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9/16-18 by what ever length you'd like and an appropriate prevailing torque nut or hex and a cotter pin. 5/8 has been mentioned but I would think that to use 5/8 a person would need to ream some components. I measure before buying 5/8, the bushing ID would be my concern not the spring or spindle.
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Old May 10, 2016 | 06:46 PM
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An inch or so in the rear will be fine, you just don't want the rear lower than the front you won't like the way it handles. The C4 should have some rake to it.
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Old May 11, 2016 | 08:36 AM
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Originally Posted by We Gone
An inch or so in the rear will be fine, you just don't want the rear lower than the front you won't like the way it handles. The C4 should have some rake to it.
Would you suggest 10" or 12" bolts for a 1-1.5" rear drop? Thanks
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Old May 11, 2016 | 09:01 AM
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Originally Posted by czarredd
Would you suggest 10" or 12" bolts for a 1-1.5" rear drop? Thanks
The kit to do this is fairly cheap and will come with new bushings. Get the 12" the extra won't hurt or you can cut them off. The best way to do the front is leave the stock bushings on the leaf spring and cut them down "minimal" to desired drop, I also shaved a little off the rubber pads on the A-Arm ends this will get you close to an 1" or so up front and you won't have to worry about glued on pads that will fail eventually and it's free. Do a search there is plenty of info on this topic and don't forget you will need a re-alignment after. Get the rake and handling were you like it and adjust camber with a level on the side of the wheel when playing with setup or it will change after alignment. The level will keep you close enough to keep testing setup. This is what worked for me and will take patients to get it right.

P.S. I would do the front first. The rear will be dependent on how much the front is dropped and handling. I like my setup with very little rake which is achieved with the taller tires in the rear and not wheel well clearance. This
will help with weight transfer to the rear wheels.

Last edited by C4vettrn; May 11, 2016 at 09:08 AM.
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Old May 11, 2016 | 09:34 AM
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Originally Posted by C4vettrn
The kit to do this is fairly cheap and will come with new bushings. Get the 12" the extra won't hurt or you can cut them off. The best way to do the front is leave the stock bushings on the leaf spring and cut them down "minimal" to desired drop, I also shaved a little off the rubber pads on the A-Arm ends this will get you close to an 1" or so up front and you won't have to worry about glued on pads that will fail eventually and it's free. Do a search there is plenty of info on this topic and don't forget you will need a re-alignment after. Get the rake and handling were you like it and adjust camber with a level on the side of the wheel when playing with setup or it will change after alignment. The level will keep you close enough to keep testing setup. This is what worked for me and will take patients to get it right.

P.S. I would do the front first. The rear will be dependent on how much the front is dropped and handling. I like my setup with very little rake which is achieved with the taller tires in the rear and not wheel well clearance. This
will help with weight transfer to the rear wheels.
Thanks! I think the front is fine now but does a rear drop absolutely require a front drop anyway?
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Old May 11, 2016 | 09:59 AM
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Originally Posted by czarredd
Thanks! I think the front is fine now but does a rear drop absolutely require a front drop anyway?
Great advice in the post above. You do not have to lower the front. Here it my 91 & 93 the yellow 93 is stock the Blue 91 is lowered 1 inch in the rear only.


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Old May 12, 2016 | 08:17 AM
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Nice comp yellow vette, I have same in 92 flavor. Are those 17" squared? The OP is going with 18's in back I believe. 1" drop rear will still work.
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Old May 13, 2016 | 04:18 PM
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I have some bolts to lower it that I'm not using - PM me if interested
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Old May 13, 2016 | 08:21 PM
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Originally Posted by czarredd
Would you suggest 10" or 12" bolts for a 1-1.5" rear drop? Thanks
Use a nylock nut and you can dial in your height exactly how you want. Measure the length of your existing bolt and add an inch or two

Last edited by 383vett; May 13, 2016 at 08:22 PM.
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Old May 15, 2016 | 06:50 PM
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Originally Posted by C4vettrn
Are those 17" squared? .
Nice 92, they all GM A-Molds ZR-1 offset.
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