Shocks! How much down travel needed?

Grit dog

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So here’s the situation. Bought shiny new expensive Bilstein shocks for the ole square and they don’t fit, basically. 2.5-4” lift shocks.
Truck has what I believe to be a 4” lift. Front springs are aftermarket lift springs and the rear is a 4” block under OE leafs. Still has some positive take to it, so pretty sure not 6” springs up front. (Although they belong under a dump truck or at least a diesel, they’re stiff)
Front shocks fit but only compressed about an inch. Doesn’t leave much of anything for downtravel.
Rear shocks are basically the same length extended eye to eye as the truck is. Zero downtravel.

Returning those as they won’t fit at all.
Looked up the applicable Ranchos and same length basically as what I have.
Obviously I’m going to need to spec my own shocks (I guess?).
How much down travel is enough? It won’t be a wheeler but It could get twisted up occasionally, driving it off road through a wash, or maybe parking on top of the hood of a Prius at the mall.
No spec 6” lift Ranchos which I would assume to be more than 2” longer than current lengths.
Would think I’d want 2-3” of compression at rest, minimum, out of a shock with 8-10” + of travel.
What you all think?
Also advice or part numbers appreciated …thanks!
 

nvrenuf

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Your best bet is to flex it without shocks to get measurements of the compressed and extended lengths and call Off Road Design for the correct size shocks. (especially since you’re not sure about the actual lift)
 

Grit dog

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Your best bet is to flex it without shocks to get measurements of the compressed and extended lengths and call Off Road Design for the correct size shocks. (especially since you’re not sure about the actual lift)
Good point and not that difficult to do. Just have to go find a good spot to use as a RTI ramp....chit shouldn't be this difficult...lol.
 

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Finding 3"of compression from a static position is... about unobtainable... The arch on a lift spring, under compression, gets longer and longer. There's isn't room and the rear shackle (yes front suspension) will swing back and hit the frame. hat why these old school lift springs are over sprung... so they don't flew enough to contact the frame. Arched springs don't flex worth a crap anyway unless it;s a Deaver or ORD thin multi leaf.
Travel can be gained as droop, which is more critical than compression when your looking for traction. The way to achieve this is with longer shocks... which calls for a taller shock mount. ORD sells a stamped Ford shock mount that gets this job done.

In order to get maximum droop you need to discounect the anti swaybar. Again, ORD has the parts for this.

Here is a quick rundown on Ford shock mounts for a longer shock.

https://ck5.com/forums/resources/extended-shock-mounts-with-rancho-shocks.53/


I may not have answered your question but it's good to know this anyway.

And...
here's where I go for shocks. Family owned. They have standard shocks made overseas but all their good stuff they make.
 

77 K20

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ORD does have a Bilstein shock spec for xxxx lift size chart:

ORD chart (click me)

They say for a 4" lift (using the Bilstein 5125 shocks) front shock should be 9.25" and the rear 11" (this is shock travel). Then you click on the product info tab they give you the rest of the shock specs:

9.25" travel: extended 24.35", collapsed 15.11", center of travel 19.73"
11" travel: extended 28", collapsed 17", center of travel 22.5"

So take some measurements at normal ride height of what the shocks are now. Then twist it up a bit with your shocks removed. Take some more measurements. Should get you there in the ballpark.

Also- did you extend your front bumpstops?
 

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