The Stovebolt Site Forums The Shop Area Driveline Rule of thumb for length of shocks?

Had a conversation with a truck friend of mine and we were discussing the length of shock needed for the GMC ride he is building. I generally measure and see what is available with about half exposed which means half in or half out....I've used a few other methods on what I "thought" would work better due to weight.

...so what do you guys use as a "rule of thumb" when buying the correct length of shock? Thanks for you input.

I recall searching tech stuff on the net that 60% of the total travel should be available for compression from ride height. Sorry don't recall the site but it seems a logical estimate when you think about the forces a shock sees- much higher on compression than rebound.

I agree. I mostly build rock crawlers but am working on a 1956 3600 build as well. Ideally you should cycle the suspension and measure full compression and full extension. However, at ride height I generally give 60% of the shock travel to compression and 40% to extension. In the rear application of a truck I would think this would be even more crucial as the ride height is generally a bit higher in the rear to account for loading of the bed or a trailer.

Thanks guys. At least I've been close all these years at 50/50 and as mentioned, I use to consider the weight factor, but on the pickups I've messed with it rarely comes into play.
Thanks for replying and I'm sure some others may chip in later.