As has been stated, no one *really* knows what it will take yet, but I think you made the best decision. Both previous gen Raptors will run 37's with minor modifications and if you were planning to spend money on a lift kit, you'll be fine. Historically, simply collars on the front and flattening a pinch weld will take care of the front and springs will take care of the back. With the coils in the back, that is probably the biggest mystery. Worst case would be new fenders and bed sides, which are inexpensive to purchase, but paint and installation will vary wildly.
Just a little verbiage for you. A "lift-kit" generally involves cutting, welding, or modifying the frame in some way and is generally considered a very bad idea on a Raptor...or any high-speed off-roader. You want as low and wide as you can get, while still having plenty of ground clearance and wheel travel. It is a fine balancing act. So while things like springs and bigger tires may actually raise the truck up, they aren't normally lumped in with a "lift kit". Just things to think about it; when I went to 37" tires, I added about 1" to the offset of the wheels and +2/+2 fenders up front and +2 leafs in the back.
In summary, don't install a lift kit unless you really don't plan to off-road it. While I'm at it....don't get bigger wheels either. Smaller wheels are better for off-road.
This forum has a ton of information tucked away in it. Up front, there shouldn't be much difference from Gen2 to Gen3 in regards to getting 37s to fit and it has been discussed ad nauseam. The back will be a complete mystery to everyone at this point, but you can bet people here will be the first to do it. Keep an eye on SVC, RPG, TMX, ADD, and any other three letter off-road shop that is heavy into Raptors.
