What performance shocks for 429 SCJ ?

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Rusty Relic

Active member
Joined
Dec 10, 2019
Messages
27
Reaction score
6
Location
New Zealand
My Car
71 mach 1 SCJ
69 mach 1
67 convertible
Hi All , I want to put a set of upgrade performance shocks on my 71 SCJ.I think the front and rear have been lowered about 2.5 - 3.0 in (hard to judge as I dont have anything to compare with ).I am having the odd bottom out issue in the front and been looking at QA1 adjustable and want to know if anyone has been there done that or can suggest a set up ? Cheers

 
I cannot speak for your car but difficult to drop 3" in front and still have a suspension unless a drop spindle. Just shortening springs for sure can cause issues like running out of travel. If you cut the springs too much then the shocks go to the bottom of their stroke and hit solid.
I have gas filled KYB shocks on my 73 vert. I did not install them PO did would have to check but I seem to recall that. The car handles fantastic but the ride quality is very harsh. If you hit a bump the gas filled shocks give more of a boom than a shock.

 
Thanks for that guys. I removed one of the front springs last night and sure enough it has been cut and the top arm has been hammering the bump stop The only springs I can compare to is a pair out of my 69 .Same height as a 71 but different wire thickness to the 429 and it looks like mine have a heap cut off. Will see if our local Mustang Supplier has them in stock.

 
Thanks for that guys. I removed one of the front springs last night and sure enough it has been cut and the top arm has been hammering the bump stop The only springs I can compare to is a pair out of my 69 .Same height as a 71 but different wire thickness to the 429 and it looks like mine have a heap cut off. Will see if our local Mustang Supplier has them in stock.
 I'd forget the aftermarket suppliers and go straight to Eaton Detroit Springs and ask the professionals for advice. They can make 1" lowering springs and offer advice on suitable shocks for YOUR car. 

You have probably seem the post linked below. 

https://7173mustangs.com/forums/topic/36373-an-interesting-and-informative-video-from-eaton-detroit-springs/?do=getNewComment

 
Thanks Geoff

Great video , he knows his stuff.

I was looking locally because every time I buy something out out the US I get a new bum bored with the freight costs (eye wateringly painful )

Has anybody got a set of uncut 429 front springs lying around that can be measured for me to see how much have been cut off mine .?

Mine also have had rubber blocks fitted between the coils to stop them bottoming I presumeP5210134.JPG

 
Hopefully this download worked. If not Google Eaton Detroit Springs and search 1971 Ford Mustang Mach 1 429 and it will find the listing for all the springs, shocks and extras needed. You can calculate shipping as well.

I'll do some more digging to find height specs if the publish it.

View attachment Product Inquiry by vehicle.html

 
Thanks again guys . Since I have started this spring thing I have decided to renew both ends with new shocks and springs.

Eaton Detroit Springs are so helpful and can supply me with a complete set up so I will work some heights out with the help of Don C`s chart (thanks Don ) and contact them again. At least by getting springs and shocks from them i only have to endure the anal pain of freight once. My last order from summit cost just over $300 USD in freight , half the cost of a pair of springs!

Have a Merry Mustang Xmas from New Zealand !

 
Here's the spring listing charts from the MPC. Spring specs changed depending upon engine, build date and options. Application chart is on page 1, spring specs are on page 2.

View attachment 47091
Great info there Hemikiller.

Now I can go back and double check my front springs. They still had original paint markings on them.

EDIT: Hemikiller, is there another page of front spring info. From the chart, it looks like mine would be a code 4M spring, 63R body, 351 after 11/9/70, 4 b except CJ & Boss. 4 sp trans. The list for part #'s and color id does not reflect 4M. Am I reading it right?

 
Last edited by a moderator:
Thanks again guys . Since I have started this spring thing I have decided to renew both ends with new shocks and springs.

Eaton Detroit Springs are so helpful and can supply me with a complete set up so I will work some heights out with the help of Don C`s chart (thanks Don ) and contact them again. At least by getting springs and shocks from them i only have to endure the anal pain of freight once. My last order from summit cost just over $300 USD in freight , half the cost of a pair of springs!

Have a Merry Mustang Xmas from New Zealand !
That's great news Rusty. 

Honestly, since the pain I went through with someone else's questionable quality front and back springs, why would anybody consider anything but Eaton Detroit Springs. As you say, you can actually talk to someone who knows which end is up.

Good luck and a Merry Christmas to you too from not so warm Ontario, Canada

 
Great info there Hemikiller.

Now I can go back and double check my front springs. They still had original paint markings on them.

EDIT: Hemikiller, is there another page of front spring info. From the chart, it looks like mine would be a code 4M spring, 63R body, 351 after 11/9/70, 4 b except CJ & Boss. 4 sp trans. The list for part #'s and color id does not reflect 4M. Am I reading it right?
Yes, there's a bunch more, I only grabbed the page with the springs shown under the 429 listing. 

View attachment 65-72coilspringspecs.pdf

 
Yes, there's a bunch more, I only grabbed the page with the springs shown under the 429 listing. 

View attachment 47092
While certainly not meaning to make this all about  my car, but wow, thanks. I didn't mean to put you to all that trouble, but there's some very useful info there for all.

Interestingly, under the listing for the 4M, C7ZZ 5310-AC, it shows 1 gold and 1 pink..... so why do mine have 1 white as well?  I would think maybe a change not reflected in the listings.

IMG_0434.1JPG.JPG

IMG_0432.1JPG.JPG

 
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