Author Topic: COPO 9561 (L72) coil springs  (Read 2784 times)

68Tom

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COPO 9561 (L72) coil springs
« on: July 13, 2009, 10:23:40 PM »
I've been doing a bunch of online research (various forums & sites) trying to figure out what springs were used on a 9561 COPO.  All charts I've seen only go up to the L78.

Also, do you think I should go with Eaton and have some made to specs, or is there a less expensive alternative?  I'm willing to spend the extra $.  Having incorrect ride height is a pet peeve of mine.

Thanks!

william

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Re: COPO 9561 (L72) coil springs
« Reply #1 on: July 14, 2009, 12:01:56 AM »
There is no difference in weight between an L72 and L78. ZL-1s used an odd spring and dialing in trim height on one of those can be trying.

Many have used the MOOG springs with no problem.

68Tom

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Re: COPO 9561 (L72) coil springs
« Reply #2 on: July 14, 2009, 12:09:56 AM »
Thanks William.  Now, were heavy duty springs standard?  I seem to remember reading that, but not 100% sure.

tom

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Re: COPO 9561 (L72) coil springs
« Reply #3 on: July 14, 2009, 12:41:49 AM »
http://www.camaros.org/images/pages/chassis/69_spring_chart.pdf
http://www.camaros.org/suspen.shtml
There is a lot of information here for the reading. The links above are a good start.
69 X11 Z21 L14 glide
looking for a 69 export model (KPH) speed
o

68Tom

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Re: COPO 9561 (L72) coil springs
« Reply #4 on: July 14, 2009, 12:56:49 AM »
Tom, I'm not finding the info on the charts, in the spring or the COPO report, hence why I'm asking. I'll check Jerry M's book when I get home.

william

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Re: COPO 9561 (L72) coil springs
« Reply #5 on: July 14, 2009, 01:59:30 AM »
For '69 Chevy introduced a computer-generated program to determine which springs to install to maintain trim height as outlined in the Assembly Instruction Manual. As options are added weight increases. At some point a stiffer spring has to be added to compensate for the additional weight. A loaded BB Camaro SS with A/C and automatic weighs quite a bit more than a basic L78 4-speed but they had to have the same trim height.

Under the right circumstances a 6-cylinder, Z/28 and BB can use the same front spring-EY or YH.

68Tom

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Re: COPO 9561 (L72) coil springs
« Reply #6 on: July 14, 2009, 02:24:22 AM »
That's pretty interesting.  As far as the console addition is concerned, I'm assuming the M40 shifter is the automatic transmission.

I think I tried doing research on this previously and kind of gave up because I couldn't find a definitive answer on what to use in a COPO.  In Jerry M's book on p. 167, there's a photo  of a COPO 427 front coil spring with a "HQ" ID tag on the spring.  Additionally, he claims on the same page that big blocks all received heavy duty suspension and used either "HQ" (part # 3955724) or "HW"  (part # 3955728) front coil springs.

Now, I look at the 1969 Camaro Spring chart and neither the ID codes NOR the part numbers are listed as options.  Hence, I still believe my original question is open, despite my research on the subject. 

Jerry, maybe you can chime in here? 

If it helps someone give me an answer, my car will be a plane-Jane '69 with power steering, front disc & rear drum brakes, no A/C, AM radio, console, M-22, MQ code 427, cowl induction hood.  Think that's about all you'll need.

Thanks again.

tom

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Re: COPO 9561 (L72) coil springs
« Reply #7 on: July 14, 2009, 03:37:27 AM »
I'm not that familiar with the big blocks, but I think the 427 is very close to the 396 in weight. I would start with the 396 weight, add or subtract based on the provided list of option weights, and any difference for the weight of the 427. That should get you started. I beleive that many of the original springs have been consolidated, and the exact spring you want may not be available from GM. Once you have the right info, a good spring shop should be able to build a set for you. We used to go to a shop near Newark (NJ) and they would build or modify a set of springs to set the height where you wanted it. Can't remember the name, and I don't know if they are still around. That was over 30 years ago.
69 X11 Z21 L14 glide
looking for a 69 export model (KPH) speed
o

68Tom

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Re: COPO 9561 (L72) coil springs
« Reply #8 on: July 14, 2009, 01:52:12 PM »
OK, so based on the 1969 GM chart, it looks like I'd use HJ front coil springs.  These apparently are correct for additional weight of 183-304.  When I added everything up, it looks like I'm around 266. 

I hope this is correct.

tom

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Re: COPO 9561 (L72) coil springs
« Reply #9 on: July 14, 2009, 03:10:43 PM »
Beforn you invest the time and money, I would try to confirm that with Eaton, or whoever you buy the springs from that this is the correct combination for your car. Time is not refundable, but if the height is wrong, can the springs be exchanged or corrected?
69 X11 Z21 L14 glide
looking for a 69 export model (KPH) speed
o

68Tom

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Re: COPO 9561 (L72) coil springs
« Reply #10 on: July 14, 2009, 03:19:08 PM »
I think I'm just going to give them a call so I can hopefully get this resolved and get a price on what it's going to run me.