Being a skeptical dude, I wanted to verify that I was buying the correct shock length for my K5. I measured the center-hole-to-center-hole distance on the current shock and then went through the Rancho RS9000 product guide and tried to find a shock who's "half-compressed" value most closely matched the static measurement on my truck.
Here are my specifics:
Static measurement (hole-center to hole-center) 18.5"
Best shock match: Rancho RS9246
Fully Compressed: 14.250"
Fully Extended: 22.875"
This allows the shock to sit basically in the exact middle of it's usable travel when sitting level. Based on my own calculations, I have 4.375" of available extension, and 4.230" inches of available compression. That's about as perfect of a match as I could find.
I don't know if this is the correct way to do shock sizing....but at the time, it made sense to me.
I would also agree with Triaged...the RS5000s are a waste of money (I have a set on my F*RD Br*nco) and they are not very good. The RS9000s are tunable, which is great for me....I have them set to "1" (full soft) to make up for the rediculously stiff springs the previous owner put on. When I go to a softer spring, I can simply turn the knobs and stiffen up the shocks!
The RS9000s really aren't that much more expensive....eat some Kraft Mac&Cheese for a week to save the extra money if you need to.
-Greg72