About Us

6567GTO · 05-02-2005, 11:06 AM

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

6567GTO · 05-02-2005, 11:06 AM

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

Ken K · 05-02-2005, 03:36 PM

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.

goatless · 05-02-2005, 04:01 PM

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.

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.

Ken K · 05-02-2005, 04:06 PM

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.

Ken K · 05-02-2005, 04:53 PM

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.

6567GTO · 05-02-2005, 04:57 PM

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.

Ken K · 05-02-2005, 05:06 PM

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.

6567GTO · 05-02-2005, 05:24 PM

Cool, thanks Ken.

Ken K · 05-03-2005, 09:45 AM

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.

bobbyj1 · 05-03-2005, 10:32 AM

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

Bob

6567GTO · 05-03-2005, 11:02 AM

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

Droptop64 · 05-03-2005, 11:12 AM

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!

Jim Doran · 05-03-2005, 11:13 AM

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 !

bobbyj1 · 05-03-2005, 11:30 AM

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

67TIGER · 05-03-2005, 03:21 PM

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?

Ken K · 05-03-2005, 03:45 PM

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.

6567GTO · 05-03-2005, 06:14 PM

Bob, your car sits beautifully. Nice stance.

67TIGER · 05-03-2005, 11:52 PM

<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.

bobbyj1 · 05-04-2005, 06:51 AM

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

Menu

About Us