There is some math involved here.....a 10 inch spring is what Fox say is what that specific shock requires for a stock to 2 inch lift. Remember that this is with the stock track, that is the stock front axle width. I use this to pass other vehicles on tight trails. Mall crawlers normally dirty their drawers at the Starbucks. At 2" lift the CV angle is just about at max for on-road reliability and daily driving. Keeping this baby happy is not doing her too much wrong. She was born & bread as a Level II, so I have to respect her for what she is currently. In the future, when everything finally falls apart, it will be not from what I did to her.
The 800 lb spring rate; I can normally get full travel on back roads going the speed limit with the coilover adjustment at about 20-25% preload. The shock can't take a taller spring because the stack up height will limit the down travel. Currently I am enjoying about 5-6" of total travel. With about 2" - 3" of UP travel.
If you elect to go with a wider track, things start changing quickly. If I had to do it all over again, I would of gone with a Twin I Beam (TIB) front end. Kept the track width the same. NOTE: if you go wider, yes the spring rate should go down if the ratio of where the shock attaches to the lower A arm is further outside. Which will be less of a ratio. Remember the stock mounting point is halfway up to the hinge point. So with Apx. 3.5" of shock travel, the tire gets about twice that. Do the math. If you elect to go wider with longer A arms that mounting point will (may) change, and so does everything else. I don't know what the other forums are stating but what I'm doing is 100% stock, simply only a shock change with some shock tower gussets. As you can see I have no added front weight to speak of. I would try a 750 lb x 11" spring if I could find one, or go dual rate where the ring that separates the springs would take up the unused 1/2" on the shock body. Either way it's all in the math. Stack up height numbers are available at the Eibach website for any of their springs. You can take other's words to the trail, but what you can do for yourself with your own pad & pencil will decide. The best resource besides this website is Kartek & Fox Motorsports Tech desk. There was another desert racing forum called "too many trails, too many something, I forget.
Running 37s, well that decides stuff for you right there. Those can't really fit under the fender & so you'll most likely will be going with a wider track width, longer lower A arms, shock placement, longer CV axles. Sorry I'd love to discuss more however now this is where I dive out the window. When I relocate to Farmington-Durango, then is where I'll have my way with a TIB front & the TIG machine. The shocks will be the last thing added to a hoop!
Have fun!
MaicoDoug
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