NEF has three different heights of factory front sights, low, medium and high. On my 45-70 I went with the FP rear and the high front sight. The high front sight is barely high enough to work. It works ok with lever action loads, but I don't have any adjustment at trapdoor load levels (the rear sight bottoms out).
I would certainly try the factory front sights first as the least expensive alternative...
>>>===> Dave