And the fun part... Suspension time! I have had a set of '14 4Runner springs for at least a year sitting in the garage, along with some Bilstein 5100's for a few months, just sitting there taunting me...
First, I found what I think is the cause of the clunk/pop in the front that I was getting recently:
Disconnect your Addco front bar if you go wheeling...
So, let's get on with it... For the front, my goal is/was to get as much out of the stock front arms as possible. I took some extra time to do this with the front. I figure (and I could be wrong!) that I should go with the softest front springs possible, which ended up being my stock front ('99 2WD springs), maybe. Some measurements:
'97 4WD springs: 16mm wire, 9 wraps
'14 4WD springs: 17mm wire, 9 wraps
'99 2WD springs: 16mm wire, 8 wraps
I didn't get free-length measurements, but probably should have. The 2WD springs barely have to be compressed to fit in the shocks, so I figured they would be more 'progressive' because they aren't pre-loaded as much. I had a couple different top plate spacers (1/4" and 3/8") to mix and match to get the extended length of the shocks to match the max droop of the upper arm (stock, droop is limited by the upper ball joint without the shock in place).
Turns out, with 4Runner 5100's (and the 4600's they replaced) that a 3/8" top plate spacer is all you can fit before the upper ball joint is the limiting factor. The shocks are about 1/4" shorter than full droop, so that pretty much maxes that out. I checked full compression of the shocks and the shock shaft has a little less than 1/2" compression when the truck weight is on the bump stop with no springs:
So, with upper arms, you might be able to get another 1/2" to 3/4" of wheel travel before shock damage occurs with 'stock' length shocks. As it stands, hub center to wheel well measurements after all was said and done:
Full extension: 25.25"
Full compression: 16.75"
At ride height: 21.25"
I only 'lifted' the front a little over an inch from stock. That is a 3/8" top plate spacer and the 5100's on the second perch and using springs meant for a 2WD 4Runner. Out of the 8.5" of travel available, I currently have 4" of droop and 4.5" of compression. I was a bit surprised when I first measured the new ride height (~22"), but I realized I forgot to put my front armor back on for that measurement. Back on, it dropped that much!