I'm in the process of doing a frame-off restoration on my 67 GTO convertible. Since the first thing I'm tackling is the frame and suspension I need some input and advice. My plan is to upgrade the suspension and brakes while I have the chance. I'm thinking of going with a complete poly bushing kit and will be buying through Scott at Summit. I'd like the ride to be that of a newer car yet not uncomfortable. Is poly or rubber the way to go? Should I install a set of Moog springs or should I go with another brand? I'm thinking of putting a set of redlines on my 14" Rally II's but might decide to go with mags and a larger diameter mag, possibly 16's.
As far as the brakes I'll be installing power discs up front and probably go with drums in the rear.

What are your thoughts people?

Anybody do a complete suspension job on their A-body that they're real happy with?

Anybody do a complete suspension job that they're Unhappy with?

Sway Bars - Is the stock front one with new poly bushings sufficient? How about the rear bar?

Thanks,
Phil

I'm in the process of doing a frame-off restoration on my 67 GTO convertible. Since the first thing I'm tackling is the frame and suspension I need some input and advice. My plan is to upgrade the suspension and brakes while I have the chance. I'm thinking of going with a complete poly bushing kit and will be buying through Scott at Summit. I'd like the ride to be that of a newer car yet not uncomfortable. Is poly or rubber the way to go? Should I install a set of Moog springs or should I go with another brand? I'm thinking of putting a set of redlines on my 14" Rally II's but might decide to go with mags and a larger diameter mag, possibly 16's.
As far as the brakes I'll be installing power discs up front and probably go with drums in the rear.

What are your thoughts people?

Anybody do a complete suspension job on their A-body that they're real happy with?

Anybody do a complete suspension job that they're Unhappy with?

Sway Bars - Is the stock front one with new poly bushings sufficient? How about the rear bar?

Thanks,
Phil

Moog springs are the way to go. When you remove the front springs, you will see how tall they are. Those springs were used to give the car a soft ride. I would use Moog #5400 springs with a coil removed from the bottom. With a coil removed, the spring rate should be around 400 lb in. Not too stiff and not too soft. With a big sway bar, the car should also handle good.

Phil, I did the front end of my '69 about 6 years ago. I used the PST "Polygrahite" master kit. I did it while converting over to disc brakes. I also used a PST 1 1/4" front swaybar.
I also did the rear suspension at the same time. I added boxed lower arms w/ poly bushings and a repro sway bar.
Both front and rear got new Moog springs and cheapo Gabriel low pressure gas shocks.

I've been very happy with the set-up but then my driving is a little more agressive than yours.http://forums.performanceyears.com/g...on_biggrin.gif

If you're going to put on 14" redlines you may as well keep it stock as you won't be able to really take advantage of the aftermarket stuff. If you do 16"+ the suspension improvements will be much more apparent. Keep in mind though, a '67 convertible is pretty flexible so it's never gonna be a canyon carver.

I am fairly sure that one of the after market suspension company is just using springs you can buy anywhere and cutting coils out of them to increase the spring rate and lower the front of the car. Those springs are made for the weight of a Chevy engine, not a Pontiac engine. A Pontiac engine weighs in between a small block Chevy and a big block. I know they use 2 different springs, one is 14 inches tall and the other is 15 inches tall.

Without knowing what options are on your car, I can tell you the stock springs on your car are between 17.5-18 inches high. The spring rate is in the low 300 lbs in range. If you remove the springs and measure the height with a tape measure and use a set of calipers to measure the wire diameter you can get a Moog part number. Go to the spring chart on the car stance thread and match up the numbers for a part number.

Good info guys, thanks. I'll look into those springs Ken. Good point on the tires Jeremy.

What bushings are known to squeak? I've heard that polygraphite is excellent in that it doesn't squeak.

I guess I'm looking for manners somewhere in between original and a canyon carver. But a little closer towards the canyon carver side without sacrificing comfort in the ride, if that makes any sense.

You don't want more than about 500 lbs in front springs on a street car or it will be too stiff. I can give you more part numbers but it will be hit and mis because they have a larger wire diameter and they are made for a big block Chevy so it won't lower the car down enough. The #5400 spring is made for a Pontiac. It will be right down the middle on spring rates with a coil removed.

Cool, thanks Ken.

The most extreme front spring that you could use on a 64-72 A body would be #6041. That spring starts out at 500 lbs in and has a .720 wire diamter. By the time you trimmed the spring to give your car any kind of stance, it would be way too stiff. For the rear you can use a CC501 or if you want a little more beef, use a CC625.

I have a brand new set of CC501's I will sell you for $40 with free shipping if you are interested.

Bob

Hi Bob, I'm interested but a question first. Did you try them out first? What was your impression of them? How did the car sit?

Thanks, Phil

I recently reworked the complete suspension on my 64 convertible GTO. I went with the polygraphite stuff in the front with a 1 1/4 swaybar, and rubber in boxed arms in the rear with a 7/8 bar. Fropnt springs were replaced with Hotchkiss 1"lowered items with 1/2 coil removed. Recently replaced NAPA shocks were retained. I went with 16x8 wheels all around and big/little radials.
There are no squeaks, the car rides smooth, handles great and is totally flat in the corners. I have not noticed any harshness except for a very minor increase when hitting sharp bumps. I'm going to try and include a file so you can see how it sits.
Good luck on your upgrade!

In addition to the other suggestions, I would suggest:

- Edelbrock IAS shocks all around
- Quick Ratio replacement steering box
- Maybe a hydraulic TO bearing clutch to elim the slop in original linkage
- Four wheel disc conversion in addition the front you are planning
- Tubular control arms front upper/lower and rear upper/lower

Getting the most out of the suspension will be all about the tires !

I never installed them on the car. I went with convertible springs in the back, and the stock ones that Ken spoke of in the front. I replaced all Front end components and used Energy Suspension poly bushings. I have no squeaks and the car rides great. Here is picture if you want to see the stance. FYI I have 15" Rally II's with 235/60 on the front and 245/60 on the rear

Bob Johnson,
I really like the way your red'67 sits.
I'm interested in getting my '67 to sit the same way.
Exactly what front and rear springs did you install? Moog 5600 with 1 coil removed on the front? Also,what would be the part # on the convertible springs for the rear?

The #5600 springs won't fit on a A Body. The inside diameter of the springs that fit 64-72 A body cars is 3.625, some spring charts won't have that exact number.

Bob, your car sits beautifully. Nice stance.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ken K:
The #5600 springs won't fit on a A Body. The inside diameter of the springs that fit 64-72 A body cars is 3.625, some spring charts won't have that exact number. </div></BLOCKQUOTE>

Sorry Ken, I put the wrong number in there.
I ment to say #5400 with 1 coil removed. Would this work in my '67 GTO hdtp? 400,TH400,no A/C.

Guys

I am not sure about the part numbers of the springs. I got them from an e-bay seller called Classic Undercar. He was a great guy to deal with. Anyway, what I do know is that they are Moog springs and that the rears are for a '67 GTO convertible and the Fronts are stock ride height for a no AC car. I have 15" Rally ii's on all four wheels and the front tires are 235/60 and the rears are 245/60. I also replaced all front suspension components and installed a quick ratio steering box. I love the way the car sits,rides and steers now!

If you want I can contact Classic Undercar and ask him for the part #'s?

Thanks for the compliments!

Bob

The springs they used from the factory were soft. A taller spring is easier to compress. If you open the hood and push down on the core support and the car moves down easy, you will know you have soft springs. If you do the same thing with a good set of springs, it does not push down easy. When you remove a coil, the spring becomes harder to compress. It drops the car down a little bit but not like you think will happen. I noticed that the 68-72 A body cars used a little bit shorter spring than the 64-67 cars. The springs still make a lot of the cars sit too high in the front. The #5400 springs are for a 68-72 car, they are 17 inches tall to begin with. The rears springs are different than the front. Variable rate springs in the rear will give you more of a performance spring. They ride normal until you get a load on them and then they are harder to compress.

Well definately don't want to cut a coil off and make it firmer! That's part of the problem.
I tried to bounce the front and can barely move it. But when I barely push down on trunk,real soft.
I measured the rocker height and it seemed to be a little high but level. I know these cars came from the factory with the fronts up a little and the rears down some(TUGBOAT LOOK).
I just don't remember them being that stiff on the front.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I recently reworked the complete suspension on my 64 convertible GTO. I went with the polygraphite stuff in the front with a 1 1/4 swaybar, and rubber in boxed arms in the rear with a 7/8 bar. Fropnt springs were replaced with Hotchkiss 1"lowered items with 1/2 coil removed. Recently replaced NAPA shocks were retained. I went with 16x8 wheels all around and big/little radials.
There are no squeaks, the car rides smooth, handles great and is totally flat in the corners. I have not noticed any harshness except for a very minor increase when hitting sharp bumps. I'm going to try and include a file so you can see how it sits.
Good luck on your upgrade! </div></BLOCKQUOTE>
MikeD. - I have to admit I like the way yours sits more and more. Why the rubber bushings in your rear arms? Was it for ride quality? It seems that yours rides more like a modern car which I wouldn't mind honestly. I have a newer 300M with a tight European suspension and I like it. Beautiful car you have there too.

I hear that Edelbrock shocks are a good investment. Anyone try those?

67Tiger, just change the rear springs. They cost less than $50.00 a set. If you still don't like the way the car is then change the front springs. How do you want your car to be in the back?

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> In addition to the other suggestions, I would suggest:

- Edelbrock IAS shocks all around
- Quick Ratio replacement steering box
- Maybe a hydraulic TO bearing clutch to elim the slop in original linkage
- Four wheel disc conversion in addition the front you are planning
- Tubular control arms front upper/lower and rear upper/lower

Getting the most out of the suspension will be all about the tires !
</div></BLOCKQUOTE>


Jim - Any advantage to using the tubular front control arms over using polygraphite bushings in the original A-trays? Those things are big bucks!
Hydraulic TO bearing clutch setup sounds interesting! Might just do that! Where to buy?

Definately getting a quicker ratio box.

OK, what tires are you thinking? I may endup selling one of my sets of Rally II's to help offset the costs of this stuff! http://pysales.com/images/sweat.gif

Phil,
I went with the rubber in the rear bushings because of what I read on this site. The general consensus is that, due to the geometry of the rear arms, there is a certain amount of flex that is needed to prevent binding when cycling through the range of motion. My past experience shows that generally, the front will control the handling, and the rear will define the ride. Notice I said "generally".
If you push on a front fender of my car, you'll swear the suspension is way too stiff - and that's what I thought when i put it back together, prior to taking it out to test. On the road, it rides similar to my '96 Impala SS I recently sold. Firm and sporty, but not annoying. The rear setup with stock springs helps to smooth the ride as well.
And - thanks for the compliment.

I got my rebuilt quick ratio box from Partsamerica.com. It bolted right in and works like a charm so far. $128!!!!!!!

Thanks again Mike! http://forums.performanceyears.com/g.../icon_cool.gif


Bob, that's incredible! $128!!! http://forums.performanceyears.com/g...s/icon_eek.gif

Is this the P/N? ...
http://www.partsamerica.com/ProductD...pe=255&ptset=A

Yes, that is the part#. It is a rebuilt unit that looked just like the one I took out (except newer)!

Bob

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ken K:
67Tiger, just change the rear springs. They cost less than $50.00 a set. If you still don't like the way the car is then change the front springs. How do you want your car to be in the back? </div></BLOCKQUOTE>

Thanks for the reply Ken.
The car sits pretty good, just a little stiff. I guess it just hasn't settled in the front as much as I think it should have. I checked my receipts and the front springs I installed are #5244. This sound about right for a '67? I might just look into a new set of rear springs,possibly for a convertible? Maybe that will bring the rear end up a tad more.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
Is this the P/N? ...
http://www.partsamerica.com/ProductD...pe=255&ptset=A </div></BLOCKQUOTE>

That looks great! I gotta get one of those. Last time I drove the GTO I was doing a "K" turn and literally forgot how many turns it took to go lock to lock http://forums.performanceyears.com/g...s/icon_eek.gif
Felt like steering the SS Minnow! "Hard a port".

67Tiger, that sounds like the right part number for the springs. They are 17.75 inches free height and rated at 315 lbs in. Those are soft springs. What kind of shocks are you using?....If you go to the Chevelle site, everyone there is having the same problem with springs. They complain about the front sitting too high. They talk about using small block springs for the big block cars....Someone mentioned using the #5400 springs for a big block with A/C LOL.

I have those springs in the front of mine and convertible ones in the rear. I believe the convertible ones are a tad taller. Ken K could probably verify.

bob

Without a part number, I couldn't tell you anything about the springs. The spring charts only use part numbers, not the application. I looked at the spring catalogs at both NAPA and Carquest for a while. They have a part number and a code for the application. If you look up the vehicle. it will give the part number. Some of the rear springs can have the same spring height and use a larger wire diameter, they don't compress as much as the springs with a smaller wire diamter.

I went to the Parts America web site and looked up rear springs for a 1967 GTO convertable. The part numbers show RCS5409S and CS5409. 2 different part numbers for the same spring by 2 different brand names. If you take off the letters on the part number, you will have the Moog part number. The convertable, hardtop and post coupe all use the same rear springs. Those springs are not variable rate, they don't start with CC. The 5409 spring is 13.44 inches free height and has a wire diamter of .554. The CC501 spring has a free height of 12.63 inches, and a wire diamter of .610. The CC501 spring is shorter but uses a larger diamter wire and is a variable rate spring. Installed in the car it might have the same ride height, I don't know for sure. The CC625 rear spring will lift the back up for sure.

Ken and all, thanks again for the info. I appreciate it.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ken K:
67Tiger, that sounds like the right part number for the springs. They are 17.75 inches free height and rated at 315 lbs in. Those are soft springs. What kind of shocks are you using?....If you go to the Chevelle site, everyone there is having the same problem with springs. They complain about the front sitting too high. They talk about using small block springs for the big block cars....Someone mentioned using the #5400 springs for a big block with A/C LOL. </div></BLOCKQUOTE>

"Those are Soft Springs"???
I would hate to see the firm ones http://forums.performanceyears.com/g...s/icon_eek.gif

Ken, The ride height isn't too bad,just a little low in the rear. My problem is with the stiffness of the front springs. Oh on the shocks, AC Delco oil shocks-all around. I put one set of these (5244) in the first time and the car sat higher than it does now. Took those out and got another set(same #) and installed those. A little bit better but still too firm.
I can go around a corner in the GTO and the front end doesn't lean AT ALL. You hit a small bump and you know it! Feels like riding in a go-kart.

I took the first set of 5244's that I removed and installed them in my '65 Olds 442. This car has a big block Olds,auto trans and A/C. The front end sat level just like it should and I can push on the front fenders and get it to bounce.
Can't do it to the GTO. This is my biggest concern.