The FE1013 Longboard 45 in black is what I have on my LHT. I installed them with my stock Conti 37-622 tires and they fit perfect. I switched to a Schwalbe Marathon 37-622 with no fitment issues. Both of these are a 700x35. As has been mentioned, if you are truly running 37's they may not work, while the fender would adequately cover a 37, the mounting hardware could contact the tire.
If you're running larger than 35's, as has been mentioned, the P50 would be the way to go within the SKS line. I assume they would fit and I've thought of going with a wider tire and getting a set of them, although they don't seem to cover as much of the tire as the Longboards, a mudflap is easy enough to cobble together and attach.