1. Yes
2. No. They are longer springs. Spring rate x travel = capacity
3. unknown to me but would be easy to figure out if you look up the specs
4. Depends what you are trying to accomplish

longer softer springs require less shock valving to control the springs = better ride quality and longer spring life.

Do it and let us know how it goes. Long term goal for myself is an 05-07 coil spring front end and ‘08+ leaf springs in the back paired with some quality shocks.

While I am a fan of building cool suspensions and making things better the reality is unless you spend the time and money doing the shock tuning to take advantage of those longer springs they are not going to ride any better then using the shorter springs from the 99-07 trucks.

rear squat is always going to happen when you put additional payload on a spring. One reason for the Excursions unique ( that is a nice way of saying poor due to way to much understeer ) handeling is the factory unbalanced spring rates. You can improve the ride and handeling by using a lower rear spring rate and adding an air bag to handle towing payloads.

The trucks do this by using a dual rate spring. The common B mod swap negates this advantage because people add the lower leafs from the excursion making the spring the stock 420 pound per inch rate.

Here, read this and pay close attention to the setup.
https://www.carlisuspension.com/prod...system-00.html

you can replicate that setup by using $125 procomp springs instead of $800 deavers and get pretty close to the same shock setup in a $80 Bilstein 5125 custom fit shock. ( not the standard 5100 excursion shock )

if you did the coil spring front I would still copy the rear setup. In my opinion it rides and handles better then the B mod setup and with air bags is vastly superior then any leaf for towing.

But if you want to put the work into a 08 spring it could be even better but not without considerable tuning.

Take a look at the procomp f250 springs, 5.5 in the rear with no blocks and 2” up front.
i’ll get Part numbers and some specs when I get some time tonight.

in the Ex height thread there are some final ride height numbers for this setup.

Joey, you said above that you were targeting 6" to 8" of lift up front, how big of a tire are you planning to run with those new to you 4.10 gears? 3.73 to 4.10 really isn't enough of a gear change to make up for big tire's with a V-10. Remember that the 6.8 is best matched with the 4.30 ratio, so 35"s mate with 4.88s for an effective 4.30-ish ratio. Of course that is for optimum all around performance and towing, a lesser ratio will still run the rig around, just with a bit less umph.

You should be good on stock axles and carriers all the way up to 5.13s, member kiaherman just put those gears in his EX.