# '68 GTO Suspension question



## mrvandermey (Jun 15, 2011)

Hi guys, I thought I would drop by and hit you up on the questions.

I just got my tubular upper and lower A-Arms for the front suspension and I just picked up my 12-bolt posi rear end w/3.55 gears. I am about to order my rear suspension (upper/lower controls arms, anti-sway bar, frame connectors, etc), but I have a quick question. In simple terms, would I be better off getting my suspension kit with adjustable upper control arms than I would be getting fixed upper control arms? If so, how would adjustable upper control arms benefit me more than fixed upper control arms?


----------



## Matthew (Feb 11, 2011)

Just my opinion... adjustable rear control arms are needed if you plan to lift the car more than a couple inches. The adjustment will allow you to keep the drive line in the correct position. In other words, when you lift the car, the rear end assembly will pull forward. You can re-center the axle with adjustment. If that's your plan, you need the adjustable control arms. If not, I would stick with the standard control arms. Matt


----------



## mrvandermey (Jun 15, 2011)

Matthew said:


> Just my opinion... adjustable rear control arms are needed if you plan to lift the car more than a couple inches. The adjustment will allow you to keep the drive line in the correct position. In other words, when you lift the car, the rear end assembly will pull forward. You can re-center the axle with adjustment. If that's your plan, you need the adjustable control arms. If not, I would stick with the standard control arms. Matt


I am not a drag racer, nor do I plan on lifting the rear of the car. In fact, I have Hotchkis lowering springs (1.5" front, 2" rear), so I will be lowering car. Should I use adjustable upper control arms if I am lowering the car?


----------



## 68Resto-mod (Nov 10, 2009)

Since you are lowering the car 2” in the rear from stock, you may need to adjust the pinion angle at the rear axle to be parallel with the output shaft of the transmission, especially under a load during acceleration. That’s what the adjustable rear uppers are for.

Dropping the rear axle rotates the axel up causing the rear pinion axis to point down towards the ground some small degree.

If the axis of the rear pinion gear is out of alignment with the axis of the transmission output shaft, the universal joints (front and rear) can bind slightly during rotation and cause vibration and eventual failure, depending on how hard you drive it. You might get away without it but why take a chance.


----------



## BearGFR (Aug 25, 2008)

Adjustable uppers allow you to make sure your drive line operating angle (sometimes referred to as "pinion angle") is correct. If it's not, then you'll have a vibration in the drive shaft that you'll probably have to correct by installing adjustable uppers.

Bear


----------



## mrvandermey (Jun 15, 2011)

So the short answer is that the nominal price difference of $80 for the entire kit in order to get adjustable upper control arms is well worth it, especially since I am lowering the car, correct?

One quick question....the suspension kit includes adjustable upper control arms, boxed lower control arms, frame connectors, anti-sway bar, bushings, and bolts to install. Where do the frame connectors connect to (where do they start and where do the end up at)?


----------



## 68Resto-mod (Nov 10, 2009)

*Rear suspension package install*

Here are some shots of by install. Hope this helps.


----------



## mrvandermey (Jun 15, 2011)

68Resto-mod said:


> Here are some shots of by install. Hope this helps.


Thanks for the pics. Is it the 3rd pic that shows the frame connectors?


----------



## 68Resto-mod (Nov 10, 2009)

Yes

Sorry for the poor picture quality. These are cell phone pictures.


----------

