Changing King Coil Springs from 16" 650lb to 17" 600lb

I've got King 2.5s installed with the max preload recommended by King — that's 5 full turns out the box. The truck rides awesome, a tad firmer than stock, but not harsh by any means. With those 5 turns, I’m sitting just under 2.5" of lift.

I'd like to hit a full 3" of lift without compromising the ride quality. I see alot of guy crank up the preload on their Kings and say it still rides great, but I just feel like too much preload kills that plush prerunner ride that kings provide.

So here’s my plan: King offers a 17" 600 lb coil (compared to the standard 16" 650 lb)... longer spring with lower spring rate . The idea is to leave my preload where it is (5 turns added) and just swap in the longer spring to gain the extra lift. Technically, the longer coil will be preloaded more but since it’s a softer spring I’m hoping its a softer ride with more lift.

Thoughts?

 

You're probably looking at 3,000 lbs on the front wheels empty, so considering that I don't think you'll gain any height changing to the lighter springs. Softer ride though...

 

If my math is right, you would gain just over 3/4” of height swapping to those coils and leaving preload maxed out. I’ve heard of other shock companies doing this (maybe Accutune) for the same reason. Personally, I’ve not tried it.

 

Some notes on preload - once you’ve cranked down on the coils enough to lift the truck, cranking down more will not change the ride quality, unless you go into coil bind. It will only change ride height and not the plushness or lack thereof.

It looks as though you have about 1” of thread showing at your current ride height with 5 turns, so getting a 1” longer spring onto the shock will be a challenge. That being said, if you can get the longer and softer spring on, you should get your desired results. I would go one more turn and see what happens to your ride height with the current coils. I bet that’ll be close to the 3” of lift you want. Six turns won’t hurt anything with the shocks or coils. In general you want 1” of preload so that you don’t get a falling rate at full droop, which is more than 5 turns in most cases.