Here are some measurements from my Explorer. I obviously can't give you the compression measurement but I can tell you that the tire hits the fender and I had to roll the lip to keep it from cutting the tire up. So it should be 7+ inches.
Here's how I lifted it.
The drivers side that I took all the measurements on.
This is from the tire to the fender at ride height.
Shock at ride height.
Tire at full droop.
Shock at full droop.
This is how I measured my shocks when I first put them on to make sure that I wasn't bottoming them out. I put a zip tie on them and after jumping the truck I checked the zip ties. As you can see they are still there but just barely.
As for a cantilever setup, think of it as a rocker arm. Let's use a 1.5:1 ratio for an example. With that ratio you can use a 10 inch shock and get 15 inches of travel. Here are a couple of pictures of Dixon Brothers cantilever.
This is what I have planned for the rear of my truck. If you plan to do something like this just make sure you use a good shock that is tunable and that can be mounted at any angle like a Fox or King. I plan to use the 10 inch Fox shocks that I have in the front now and then I'm going to use a 12 inch King triple bypass on the front.
