I realize that this posting is kinda old but hopefully not to old to get some questions answer.
I was out in the bone yard yesterday looking for some Exploder springs and came across a real nice set. I was wondering approx how much lift would I get when I put the Exploder coils in? I too want to run 31's but the weight of my family and I in the BII is too much.( not that Im a real heavy guy ).
Ive got to go up a bit. So Ive come up with an idea of putting the front coils from the Exploder along with a set of coil spacers Like what was in the F-150's up front and at the same time a set of Exploder leafs along with a factory blocks out of a Ranger. ( I think the blocks are 2" that Rangers have)
Ive also noticed that some of those Rangers have like 9 coils in there coil springs instead of the normal 8 that the BII's have. Would that bring the Bronco up even more??
Do you think that this would work and if so approx ( rough ball park figure )how much lift would I get. Im suspecting Ill be able to clear the 31's.
Would I be right??

 

You could probably add the spacers up front and blocks in the rear and get 3"-4" of lift or more, but keep in mind, anything over a 2" lift is going to affect your camber, caster, steering geometry, and driveline angles - which will require shims or 'angled' blocks on the rear leaf perches as well as other pieces and parts to correct your front end geometry. IMO, the safest (although it be expensive) way to lift for 31s is with a complete lift kit (Skyjacker, Duff, etc.). Not saying you can't get by without going that route, but you have to understand that the front TTB axle, steering, and drivelines have to align a certain way or you're asking for problems. I think the cheapest option would be a Duff Stage 1 3.5" lift kit, but I personally would go with a Stage 2 kit with the leaf springs, not blocks or add-a-leafs, unless you have some good used leafs that aren't weak (which happens to a lot of the BIIs causing rear end sag). That is my $0.02 and opinion(s), for whatever it's worth.

 

I picked up a wrecked 92 4.0 Ranger ext cab for parts and put the springs/spacers in my Bronco II which I am working on.The Ranger had 235/75/15 tires with plenty of room so I originally planned to use those but when I swapped everything over I found I had gained about 3" of lift so decided to go with 31's instead.The Ranger had a 1" spacer under the front springs which I re-used in the Bronco II, I am guessing the previous owner had them installed to level the truck.The camber is all wonky right now, I picked up some Moog adjustable camber/caster shims which I hope will bring it into specs.I had some Rancho shocks on the front of the Bronco II which have enough extension to work with the added lift but my rear shocks wouldn't fit anymore.I did some cross checking on a shock chart and found most 80's and early 90's F150's had a shocks with the same ends as the Bronco II but were a couple inches longer so I picked up a set of those for the rear, it seemed cheaper than buying some Bronco II lift shocks.The only modification I had to do was the lower mounting bolt for the F150 shock is larger than the Bronco II so I had to drill out the hole in the shock bracket a bit.The F150 front shocks have the same ends as a Bronco II as well and are a couple inches longer but I haven't checked them to see how they fit.

 

You'll want to probably adjust closer to zero camber. 3" of lift is going to be borderline - you want your axle pivots up front just slightly above the hub centerlines and no more than 1 or 2 degrees difference (if I remember right?) difference in angles for your pinions (t-case and differentials). Any more than that will cause vibration and driveline damage. This is why even the Duff 3" lift kits come with drop bracketry and the parts you need to correct these problems.