Need Coil Spring Info

[ohyaa]

I have a 67 coupe with a 289/C4. It now has aluminum heads and intake. It has a negative wedge kit and Pro Motorsports progressive springs in front and 4 leaf standards in the rear.
The nose is still too high. Is it possible to use 65-66 1 inch drop springs such as the one NPD sells to bring the nose down? Those springs are the 480# vs. 550# for the 67 up version.

Thanks

 

[zookeeper]

I'd cut 'em until you get the car where you want it.

 

[Tim65GT]

ohyaa
Is it possible to use 65-66 1 inch drop springs such as the one NPD sells to bring the nose down? Those springs are the 480# vs. 550# for the 67 up version.

I have those very springs getting delivered today. I originally was going to replace my sagging springs with new GT springs, because I didn't want a harsh ride. I seen where a guy cut one and a half coils out of the GT springs, and it looked like a nice stance for his stang, so I cut one coil out of the new GT springs to get it down a little , but it was too much. So if you are going to cut, only cut 1/2 coil at a time.

 

[iskwezm]

cutting 1 coil on a 620 will make it flop around when you jack it up

 

[Jimmys66]

I have the progressive springs on the front of my 66. I love the spring rate, but after lightening the front of my car they also made the front a little too high.


I cut mine to get the stance I wanted.

Saying that........ with these springs I cut 1/3 of a coil and it dropped the nose 3/4". Becarefull how much you cut the first time. 1/2 coil would have been too much for me.

My old stock springs had 1 full coil cut and it lowered the car 2". Different spring rates will produce different results. Be conservative, you can always cut a little more off if it's not enough.

 

[ohyaa]

Thanks for the replies so far.

Other than the spring rate is there any difference between a 65/66 and a 67 up spring?

Any 67 up people use a big block spring and cut it down? Trying to avoid a too stiff ride. This car is street only.

 

[mikethebike]

If you make a compressor from all-thread some nuts and plates you can compress the spring, heat it to 350 for 2 hours, turn off the oven and allow it to cool overnight in the oven and you will shorten the spring without changing the rate.

 

[Tim65GT]

I put the NPD 480# 1" drop springs in and now it is too low and it is too stiff.

ohyaa
Thanks for the replies so far.

Other than the spring rate is there any difference between a 65/66 and a 67 up spring?

Any 67 up people use a big block spring and cut it down? Trying to avoid a too stiff ride. This car is street only.

I was wondering about the big block springs too. Maybe the rate is some where stiffer than a Stock GT springs but softer than the NPD 480# springs.

 

[CraigMBA]

OP:

Is your car fully assembled, full of fluids, and moving under it's own power?

I have the PMS springs in front of my '65. They were perfect untill I got aluminum heads, intake, headers, and relocated the battery. Then they were too high. I cut half a coil off of the end with the wide spaced spring pack. The tightly wound side is designed to keep preload on the spring when it's fully extended, preventing the "flopping around" that guys get with 620's.

 

[tweet66]

I though the factory 65/66 springs are one inch shorter than 67/68's to begin with??? I would assume (there's a problem) that using the 65/6 drop springs would lower a 67 2"...

 

[CraigMBA]

I though the factory 65/66 springs are one inch shorter than 67/68's to begin with??? I would assume (there's a problem) that using the 65/6 drop springs would lower a 67 2"...

Are they? It really doesn't matter. There's a lot more to a spring than it's uncompressed length.