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Discussion Starter · #1 ·
Question about my 67 coupe.

289 v8 with mild build and efi
C4 auto
Stock rear diff, unsure what gears
Shelby drop up front and total of 1.5 inches lower than stock.
Heavier sway bar up front and aftermarket rear sway bay.

Here is my question. Under hard acceleration the back of the car feels like it squats down and shifts the back of the car left making it steer right, it corrects after letting off the gas. It requires a bit of steering wheel correction to keep it on the road. Bushings and front end pieces all seem to be in good working order.

Any suggestions for fixing it or is it not a big problem?

Thanks
 

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Question about my 67 coupe.

289 v8 with mild build and efi
C4 auto
Stock rear diff, unsure what gears
Shelby drop up front and total of 1.5 inches lower than stock.
Heavier sway bar up front and aftermarket rear sway bay.

Here is my question. Under hard acceleration the back of the car feels like it squats down and shifts the back of the car left making it steer right, it corrects after letting off the gas. It requires a bit of steering wheel correction to keep it on the road. Bushings and front end pieces all seem to be in good working order.

Any suggestions for fixing it or is it not a big problem?

Thanks
You check tire pressure, particularly on the rear?
Same size and brand tires?
Have you checked the alignment?
 

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Low tire more than likely. Can also be caused by a radial tire pull. If all 4 tires are the same size, I would rotate them and set the tire pressure.
 

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Could also be a blown out front eye bushing on one spring, or loose/damaged u-bolts or shock plates on the rear axle.
 

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Did u change the rear axle when you went from 6 to 8?
Did u change the rear springs?
Bad front or rear shock?
Broken motor mount?
 

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This is just one other potential. When I was drag racing my mustang we aligned it with me pulling up on the hood. Mostly it is a toe issue. If your toe is slightly different from one side to the other, romping on the car which will lift the front end will amplify the toe being slightly out and can cause it to try and drift to one direction or the other.


Loose leaf spring u bolt/s or one leaf weaker than the other could also cause one or the other leaf springs to want to shift the back end of the car.


I am also one of those people who runs a rear anti-sway bar. I bought longer bolts and spacers for mine so I could put the arms of the bar level with respect to the plane of the ground under the car. I hope I am explaining this well enough. It keeps the bar from trying to pre-load the rear and more importantly, pre-load one side more than the other. With the bar level at ride height it is fairly neutral to both frame rails normally so when you nail it you should get even force on both ends of the bar pushing up on the frame and so you get a straight and level launch.
 

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Discussion Starter · #7 ·
Thanks for all the quick replies

1. I will double check tire pressure

2. To my knowledge its always had a v8

3. Would the shelby drop contribute to this?

4. Macstang. I like the idea of the adjustment on the rear sway bar, i will look into this.

I maybe forgot to mention the car does squat in the rear as it shifts left under the acceleration
 
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