I'm going to do basically the same thing with an axle setup I am picking up shortly from another member on here. Paul's is a '46, but pretty much the same dimensions.
Problem with these later axles vs the earlier ones (like '28 to '34) is the fact the spring perches are way out on the ends to accomodate a wider spring used in the later versions. What this does is put your wishbones very close to the tires if you split them, which can interfere when you crank the wheel all the way over hard. The fix is usually to bend the radius rods slightly inward toward the front which moves the back portion closer to the frame.
Another problem is that the stock radius rods are designed to put the spring in front of the axle. Norm Grabowski was one of the first to solve this problem by turning the spring mounts around backwards, putting the spring behind the axle. He then used one of the first fourbar setups as radius rods.
What I am going to do is cut off the spring perches altogether and then hang the spring behind the axle from perches I will fab up to go on the wishbones themselves. I may have to have a custom spring made to the correct length, or at least have a custom main leaf made up and use what leaves I can from the old spring.
You are also right in your assumption that the dropped versions of these axles are even tighter in the very end portions, because the dropping process consumes some of the length. When they are dropped these axles almost always need dropped aftermarket steering arms to clear the drop.
Oh, and finally, the '42 to '48 axles are wider by a few inches than the earlier axles, so your tires will be out a little more than if you used an earlier one. Not really a problem, but I just wanted to mention it.
Don