First off, a low-cut filter will cut freqs (with a sharp slope - the 18db/octave part) usually somewhere below 75hz (the actual freq depends on the board). It's typical to turn on this filter on any track that doesn't have this low a response (vocals, guitars, drum overheads) to remove the mud that can waste song frequency bandwidth. And of course, you can use it in the scenario that you are currently experiencing!
The "kick you in the chest" frequency is around 85hz. You want to adjust the low-end of the bass and/or the kick so that they work together and provide a solid foundation. One shouldn't over-shadow the other and both should still be clearly defined. You do this by carving out a small part of any frequency range that is overlapping between the two. Doesn't take much, so don't abuse that EQ! (You will need a parametric eq to do this - forget using a graphic!)
hope this helps...