Another concern is with most SAS projects I see is the amount of lift. Is this for clearance of the pumpkin under the oil pan? or personal choice.
My truck run's 36's and they rub SLIGHTLY. I built it to run 35's, but had a chance to get these 36s for cheap, and I like swampers, so....
I want to keep my rig as low as posssible running a max tire size of 35 on the SWB
You can build it as low, or high as you want to. I do not think the oil pan's are in the way. My 4.3 certainly is not. The sump is behind the axletube, and housing. The problem you're going to run into is that the Gen1 fenderwells arent big enough to "Stuff" 35's or 36's WAY WAY up in there. I could take the 2 inch BL off my truck if the front tire wells were larger, or I put some serious limiting bumpstops in there(I have none:8).
..It would be nice to have tons of droop....How much travel can one reasonably expect to get with leaves?
I really do not have a way to accurately measure this, BUT you'll obviously get more with coils. You've got to keep in mind though that TOO much droop is not good. You've got the limits of brake lines, driveshafts, steering linkage.. etc to contend with. Some folks have to put limiting straps on their axles to keep them from literally falling out. I've seen some CRAZY stuff happen with home brew coil links. better do your homework if you're going in that direction.
The BEST positive to a Coil setup is this.
You can mount the axle as far forward as you want to have an awesome approach angle, AND you can run as big a tire as you want to.
On a leaf sprung vehicle, the Front leaf mounts will ALWAYS be in front of your tires unless you're running 44's(not realistic for us), and the Springs will Hinder larger tires from turning to full lock. The TSL lugs 36's tickle the leafs when I turn full lock to the left. I would not be able to run ANY tire size larger than this without taking that into consideration.