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'67 GTO Rear suspension

9.4K views 17 replies 7 participants last post by  Mine'sa66  
#1 ·
Just had new front suspension installed and it now appears that the rear is just a bit low. Rides nice and I am sure most would never notice. But, I would like to have a slightly more aggressive stance. The mechanic is recommending air shocks. Thoughts??
 
#2 ·
You can, but then you are using the air shocks as a crutch and putting additional pressures on the upper shock mounts which were not intended to hold the car up. If you use only 1 airline to connect the 2 shocks, you may find that the car can sit uneven as one shock may supply more pressure than the other.
 
#6 ·
The correct way would be new springs, however, possibly a simple 1" spacer under the spring. You did not say what year. The factory did have a slight lowered rear, but I don't like it. I like level or just a little above - or realllly jacked up with big tires hanging out.

Depending on year, the early cars use a bolt/hat to hold the lower spring end secure. Later use a spring perch having a "tube" that the spring fits over.


 
#8 ·
You can try it and see, not a big investment. Just get under the car and see what the spring perches look like just to confirm.

Secure the car from rolling. Simply unbolt the shock at the bottom and jack up the rear of the car high enough until the springs can be pulled out. You may want to install new rubber insulators at the tops of the springs while out. I believe the spring pigtail at the top of the springs, along with new isolator, may have to be "clocked" to fit into the pocket. Look up inside and you may see where the spring pocket has an indent (much like the front springs lower control arm pocket) and the end of the pigtail will set in it. Then install the spacer, put the spring on top, drop the weight of the car on the springs to compress, and bolt the shocks back up. Done.

I think that covers it. Your mechanic, if he does it, should make fast work of it with all the correct pieces. If you don't like it, then go new springs, but I would get a custom spring company that will make a spring for your application. A new stock height spring might get you right back to where you are now.
 
#15 ·
That's an awesome stance. I just installed the Ames S352's which were originally installed in the convertibles only. They are supposed to give a nice ride but a slightly higher rear stance. I haven't installed the body yet, but it looks like Mine'sa66's car, I will be very happy. Nice job, Sir.
 
#16 ·
DANGER, WILL ROBINSON!
AC 45H2005 has a large diameter top, and is for earlier cars! I think officially all 67's have pigtails top and bottom, but have seen rumors that it was actually a midyear change. Early cars were full diameter top and pigtail bottom. Later cars were pigtail top and bottom. Early axles had flat spring pads and spring bolted to the pad. Later cars had a raised boss, and the pigtail fit over the boss--no bolt. These cars are 50 years old, and axle and/or frame could have been swapped.
 
#17 ·
The spacer under the spring is definitely a viable option. Back in 1967 my car came off the dealer lot with the rear low - I really don't know what Pontiac was thinking. I made a trip down to the local Napa store before the GTO was a week old and bought 1" spacers and they stayed with the car for 30 years. With spacers there is no difference at all in ride quality, and a 1" increase at the axle is a little under 1-1/2" by the time you get to the end of the bumper.

The 67 rear is easy since it is only spring preload that keeps the spring on the perches. As Jim said above, just remove the shock bolt and jack the frame up until the spring is loose enough to slip the spacer in place and then lower the car back down and put the shock back in place. There is actually more preload so even less chance of the spring falling out than stock.

They actually still make the same ones I put in 53 years ago. Only turn-off is the current price which is ridiculous. Here's the link: 1" spacer from Summit Racing: