Upper control arm bushings

[340_duster]

Would it be a good idea to install offset upper control arm bushings to make up some of the lost length in the control arm , when the K frame spacers are installed? Has anyone tried that and if so , what positioning worked the best?

Thanks

 

[Kernel Sanders]

Sorry I have to ask because I've never heard of this before...

Kframe spacers on an Abody? why and for what purpose?

Please forgive me, I am curious as I've never heard of doing this.

 

[340_duster]

Sorry I have to ask because I've never heard of this before...

Kframe spacers on an Abody? why and for what purpose?

Please forgive me, I am curious as I've never heard of doing this.

Spacers are used between the kframe and the body, when building a 68 hemi super stock car. This was done to lower the height of the carbs, to be in compliant with NHRA rules, regarding fender to carb height

 

[Kernel Sanders]

Ah thank you kindly! Being a non racer Id had no idea of any requirement such as that. Thank you again

 

[72bluNblu]

It wouldn't be a bad idea to install the offset bushings that's for sure.

As far as how, if all you were trying to do was make up for lost length you would install both bushings so that the offset was toward the frame (fat part of the bushing facing the ball joint, skinny part to the frame).

I'm not sure I'd be inclined to install them that way though, I'd probably still install them for max caster because I think that's a bigger issue. How tall are the spacers? And, I guess if this is a Hemi car staying close to original specs are you running radials up front? Or bias plys?

 

[340_duster]

It wouldn't be a bad idea to install the offset bushings that's for sure.

As far as how, if all you were trying to do was make up for lost length you would install both bushings so that the offset was toward the frame (fat part of the bushing facing the ball joint, skinny part to the frame).

I'm not sure I'd be inclined to install them that way though, I'd probably still install them for max caster because I think that's a bigger issue. How tall are the spacers? And, I guess if this is a Hemi car staying close to original specs are you running radials up front? Or bias plys?

Spacers are 1/2 inch thick, tires most likely will be bias ply

 

[72bluNblu]

Spacers are 1/2 inch thick, tires most likely will be bias ply

With bias ply's and a stock ride height I wouldn't worry about the max caster install, you could just install them to lengthen the effective length of the arms.

If you did install radials I would probably do the max caster install, or maybe even split the difference by installing a stock bushing and an offset, ie, use an offset in the front leg of the UCA arm and a stock bushing in the rear. That would lengthen the arm slightly and give a small amount more caster adjustment. Typically you install the bushings like indicated in the picture below for max caster, so the front arm is effectively longer and the rear arm is effectively shorter, giving more caster. An offset in front and a stock bushing in the rear wouldn't shorten the rear arm, which would be better for you, but it would also only give half of the caster addition that using two offset bushings would give.

Also, something to consider would be using the later FMJ spindles. Those spindles are slightly taller, which would help compensate for the 1/2" drop on the K member. Not sure if you're using the BBP though, and of course the brakes would be different. Sounds like you're trying to be pretty accurate, and of course the later disks would be different.

 

[340_duster]

With bias ply's and a stock ride height I wouldn't worry about the max caster install, you could just install them to lengthen the effective length of the arms.

If you did install radials I would probably do the max caster install, or maybe even split the difference by installing a stock bushing and an offset, ie, use an offset in the front leg of the UCA arm and a stock bushing in the rear. That would lengthen the arm slightly and give a small amount more caster adjustment. Typically you install the bushings like indicated in the picture below for max caster, so the front arm is effectively longer and the rear arm is effectively shorter, giving more caster. An offset in front and a stock bushing in the rear wouldn't shorten the rear arm, which would be better for you, but it would also only give half of the caster addition that using two offset bushings would give.

Also, something to consider would be using the later FMJ spindles. Those spindles are slightly taller, which would help compensate for the 1/2" drop on the K member. Not sure if you're using the BBP though, and of course the brakes would be different. Sounds like you're trying to be pretty accurate, and of course the later disks would be different.


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Thanks so much for that information, you have definitely given me something to consider.