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twilightTA
10-19-2024, 09:04 AM
New member here with a 1977 Trans Am LS swap that has a PTFB GT suspension (new springs, sway bars, Viking double adjustable shocks, solid subframe bushings and subframe connectors, fast steering kit). 17x9 snowflake wheels with 255/285 Continental ExtremeContact tires.

The control arms are the only items that are really stock at this point, though their bushings and ball joints were replaced about 10 years and 6000 miles ago).

It’s just a street car but I do enjoy carving corners but still want it to drive nicely on the street.

Are there any benefits to just replacing the upper arms? I like the current ride height and don’t want to risk messing with that hence I was thinking to avoid the lowers.

csouth
10-19-2024, 07:09 PM
Most of the newer stuff will have offset shafts that can allow a little more camber and some improved caster built into the arms.

cdrod
10-24-2024, 01:23 PM
Howe Racing makes rebuildable ball joints that can be assembled with longer studs that move the suspension pickup points to improve suspension geometry. You can also get tall ball joints made by ProForged from Holley but these are not rebuildable or as customize-able. These taller balljoints don't always work well with the stock upper arms; the tubular upper arms are typically shorter to allow the negative camber gain during suspension compression.

I used the Howe ball joints with stock lower arms and stock spindles with adjustable upper arms from SPC. Ball joints: +.3" lower, +.9" upper. I was able to set alignment caster at +6 degrees with -.5 degrees camber. The car isn't a corner carver but it tracks sooo much better than the stock suspension geometry.

Here's some links:

https://howeracing.com/collections/howe-precision-ball-joints

https://www.holley.com/products/suspension_and_chassis/ball_joints/ball_joints/parts/101-10473?srsltid=AfmBOoo2zB1hxXjxJBITfEQHHZDNzbPk-IskbOdP9lJhsYTxAyh_Ti9g

https://www.spcalignment.com/index.php?option=com_spc&task=part_description&pid=94320

Rodney

Hotwire
10-25-2024, 04:46 AM
As mentioned above, getting aftermarket arms will allow you to improve the geometry of the factory setup and give you more confidence when you decide to toss the car into a corner.

I went with SPC fully adjustable uppers, proforged 0.9" taller upper balljoints and 0.5" taller lower balljoints. This lowered the front by 0.5" but corrected bumpsteer, the steering wheel doesn't try to jerk out of my hands when I hit bridge abutments and stays planted in corners instead of trying to wiggle around. I did a full explanation here: https://www.chevelles.com/threads/good-handling-a-body.1138157/page-2?post_id=11467781#post-11467781

ULTM8Z
10-25-2024, 06:10 AM
It was night and day for me when I put on aftermarket tubular arms and capitalized on the ability to dial in more caster.

twilightTA
10-27-2024, 11:45 AM
It was night and day for me when I put on aftermarket tubular arms and capitalized on the ability to dial in more caster.

Thanks everyone for the replies. @ULTM8Z what aftermarket arms did you go with and did you do uppers and lowers? Looks like you have a 2nd gen F body as well.

ULTM8Z
10-27-2024, 02:26 PM
I had found some used ones on Ebay, made by Performance Online. They looked decent, and were a really good deal, so I figured I'd give them a shot.

Certainly not one of the big name brands and my suspicion is that there are better ones on the market, but for what I do with the car (weekend cruising for the most part), they fit the bill just fine.

I've had them for probably a little over 10 years now and they've worked flawlessly.

twilightTA
10-28-2024, 03:07 PM
You guys with the SPC arms, did you have any issues setting the alignment with them? I see a few mentions across the web that their non-shim based adjustment can be a challenge for alignment shops to figure out (though I personally like the idea of not loading up a bunch of shims). I like that the SPC arms also have a rubber bushing option as I was worried about NVH issues too.

Hotwire
11-07-2024, 06:17 AM
I'm running the fully adjustable SPC upper arms w/ rubber bushings on my a-body. Have been able to dial in as much as 8 degrees caster with no issues. Using proforged 0.9" taller upper balljoints on them.

ULTM8Z
11-10-2024, 07:51 AM
You guys with the SPC arms, did you have any issues setting the alignment with them? I see a few mentions across the web that their non-shim based adjustment can be a challenge for alignment shops to figure out (though I personally like the idea of not loading up a bunch of shims). I like that the SPC arms also have a rubber bushing option as I was worried about NVH issues too.

Finding an alignment shop that works on these old cars at all is a challenge these days... lol.

twilightTA
11-15-2024, 07:02 PM
Thanks all - I found a good deal today on the SPC control arms - the 97130 model. I’m planning to use the ball joints that come with them for now - they’re 1/2 inch longer than stock.