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I installed Timbren SES units on my previous Tow Vehicle (that uses Leaf Springs). I also installed Timbren SES units on my new Tow Vehicle (that uses Coil Springs). Love them so much, my future Tow Vehicle will immediately have Timbren SES units installed as well. Especially since I have a few trailers that cannot accept a Weight Distribution Hitch.
For me, Timbren SES units isn't a means to "over load" that specific Tow Vehicle. re: Make it tow or load it down more then it legally should. IMO, factory suspensions are made "soft" - made more for passenger comfort and less for loading (that many drivers don't do). To create more firmness under load and for attached trailers (like utility, boat, 5ers, etc) that don't use a Weight Distribution Hitch, I install Timbren SES units instead. Low cost and easy install. And if adjusted properly, Timbren SES and Weight Distribution Hitches can be used together.
For a gapping, recommend installing with the 1" Spacer. Drive around for a few weeks. Then, remove the 1" Spacer. Then drive around for a few weeks. Compare the empty comfort and loaded comfort of both. Then, use either install method that works best for you. For my setups, I like 1/2" gap - for empty loads. If needed, one can create their own 1/2" spacer plate as well. Whichever works best for your setup.
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