I'm chasing fractions of an inch of travel here. But here we are.
Starting out, I was running my Extended length Radflos with 650lb/in coils set at 2" of lift. They were dramatically better than the 5100s with 600lb/in coils and the ToyTec/Nisstec/FBG adjuster conversion but still jerked the Xterra to the side when the tires dropped into a hole.
Next I added a 0.5" thick (1" lift) spacer to them and the bumper/winch combo leveled it back out. Even with that spacer, my UCAs were still contacting my fender liners at full compression so I had to add longer bump stops which left me nearly an inch of my shock stroke unused.
That was an improvement in ride quality and it got me thinking; if we can run a 1.25" thick (2" lift) spacer on top of OE coil over assemblies then why can't we run them with Rads/ect to relocate the shock travel window down and improve the up/down travel balance?
So I searched around and thought about it and decided to try it. I have a pair of the PRG 1.25" thick (2" lift) spacers in the shop so the last time I had the X on stands, I pulled the coilovers and swapped to the taller spacers and dropped my coilovers back to the same ride height I was at.
You can see the difference in full extension here.
0.5" thick (1" lift) spacers
1.25" thick (2" lift) spacers
That was a big improvement in ride quality. Places I had been topping out my shocks around town were now buttery smooth. But, I was at the limit of my suspension joint travel. I'm pretty sure it is my lower ball joints that are the bottleneck but the shocks just barely went into place with the 1.25" thick spacers.
I didn't expect this to be permanent since I was obviously stressing the joints and the last thing I want is to start killing them so I picked up a pair of PRG's 7/8" thick (1.5" lift) spacers for it. You can see here that my upper ball joint was making contact with the top of the coil over at full extension as well, so it was just too much.
With the 7/8" thick (1.5" lift) spacers installed, I'm roughly 3/8" from the suspension joint down limit now. That should help keep everything happy and healthy. It also gives me the maximum amount of down travel I feel like an OE width setup can run with OE LCAs. The added benefit is that I now have use of all of my shock travel too!