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Discussion Starter #1
can I get some help from my FSB brethren? I am building a truck with 78 bronco coil springs ( I bought 1-2" lift springs and it seems that they will be too short sadly)

my question do we have a feeling of which springs from which manufacturers are short tall taller tallest?

Example are 4" jbg springs going to ride massively lower than supercoil 5" springs? etc...

Anyone used multiple different brands and sizes of springs that could weigh in? I have a cummins 4bt a winch and a bumper so heavy front end and the 1-2" springs just wont be beefy enough. Definitely dont want a huge amount of lift so maybe whats the softest 4" spring? or does anyone make stiff 3" springs etc?.
 

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Discussion Starter #2
picture of motorless ride height


this is without the 750lb motor or the winch or bumper so you can imagine that the 1-2" springs will settle quite a bit with all that added weight.

One last thought I don't need crossmember comments as its already torched out and replaced by a low profile one. This is just asking you smart guys for coil spring help! I'd love it to ride like this or just a tad taller once the wieght is on it
 

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FYI, I started a coil spring thread a while back in the SAS section. It may help.

It may be difficult for you mid-build. But if you could determine your sprung corner weight, that would help you dial in your coils. Knowing this, the free length of the coil and the coil lbs/in rate, you can determine exactly what the compressed length of the coil will be.

For example, let's assume you will end up with a 1500lb sprung corner weight with the Cummins and the bumper/winch combo on there. Using a JBG 4-4.5" spring with a 415lb rate and a free lenght of 20" you would end up with a compressed spring height of 16.38" (spring free length-unsprung corner weight/spring rate). This is the best way to figure out these height issues.

The softest spring your likely to find is a 300lb rate. That's going to be to soft for what your doing, assuming you don't care a whole lot about suspension flex. I would stick with something around 400+. But for argument sake, if you used our 300lb 4" coil (19.75" free length) you would end up with a compressed coil height of 14.75".
 

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1996 Ford Bronco
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For a 78 application/spring, the Wild Horses springs will work as well from the first gens, per WH guys. They said the rule of thumb is to knock off about an inch (if I'm not mistaken) for lift height. So a 4.5" spring on a 66-77 would be about 3.5" on a 78-79 (or other FSB I assume).

The post above is a much better technical way of figuring this out. I just thought I'd mention WH springs as another option.

I have the JBG/Superlift 1-2" coils on my 78. Every suspension component and related bushing has about 1000 miles on them. I have the stock 400 with an aluminum intake, but stock bumper and everything else front end wise. My net lift up front was about 1.5", for what it's worth.
 

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Discussion Starter #5
All wonderful information. Thank you for the help, gentlemen. I can wait until all the weight is on to change the coils. That won't be a problem. How do I weigh each corner individually to figure out sprung weight.
 
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