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'73 Camaro NETO/N
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Discussion Starter · #1 ·
I recently ordered a custom set of coil-overs from Mike at Viking Performance. I thought it was about time to get with the times, and replace the old Koni SPA1 single adjustable coil-overs with a modern double adjustable shock.

For Comparison...

Koni 8216 1908 SPA1, 6.37" stroke, 19.13" max length, 12.76" min, 15.95" recommended ride height, 14" spring, 125#?

Viking Crusader C-315AM-D, 9.00" stroke, 23.75" max, 14.75" min, 18.375"-20.25" ride height range, 14" spring, 110#

The current installed height is at 17" with the lower shock perch in the highest position. That's only 2.13" on extension. After repeated measurements, with tires on and off, I concluded the longer travel on a lower mounting point will work without any interference. Thoughts?

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You’ll be fine, just did something similar on my dads nova. You’ll use a lighter spring to let the coilover compress more. We used a spring that got us 65-70% compressed with the weight of the car on it (left the spanner nuts for the coil springs so they have a good ways to go up, or down.) If you’re at 17” length with the cars weight on it now, and your new coilover/spring combo is set up at the recommended 18” length with the cars weight on it, you can just drop the lower coilover mounting brackets 1” lower on the rear end, and you’ll have the same ride height.

You may want to look into a 16” spring, but I’d try it with the 14” spring if you already have it. Those new shocks you got are pretty long.
 

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Something else to watch for, depending what you have for a crossmember, going to a longer shock and having a bunch of extension can put the driveshaft close or into the crossmember. Only mentioning it because I ran into problems when I went to a small radial from a bigger tire the car was built for. So check when the rear is hanging to make sure you have some clearance.
 

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Discussion Starter · #5 ·
You may want to look into a 16” spring, but I’d try it with the 14” spring if you already have it. Those new shocks you got are pretty long.
I was thinking the same thing but the 14" spring is what that shock is designed for.
 

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Discussion Starter · #6 ·
Something else to watch for, depending what you have for a crossmember, going to a longer shock and having a bunch of extension can put the driveshaft close or into the crossmember. Only mentioning it because I ran into problems when I went to a small radial from a bigger tire the car was built for. So check when the rear is hanging to make sure you have some clearance.
The driveshaft is running uphill towards the rear. I wasn't happy with the driveline operating angles, so I was able to shim up the trans mount 9/16" to raise the crank centerline. I adjusted the pinion angle accordingly at about 1.9* below crank centerline. This centered the shaft better in the hoops. I measured the full range, and the shock will be fully extended before the driveshaft contacts. In an extreme situation, the anti-sway bar will prevent the new shock from hitting full extension. At that point, I'd probably have a lot worse things to be concerned about. While I was busy re-adjusting everything, I extended the Instant Center further out and down. The IC is now out to 57.5", just at or a little below the "anti-squat"/neutral line. As you mentioned, the extra length gives more adjustability to get the suspension in balance.
 
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