ok,
ive made my mind up i want real train horns… but…
im a little confused with which ones to go for so please any advise would be very much appreciated… 
k3 ? k5 ? LA… HA… whats the difference 
which one is the loudest?
im going to have to mount them seperate with the special brackets so which sets best for me ?
many thanks,
jason.
k3’s are louder they say but id go for k5’s. LA is for the low manifold and HA is the high manifold. As for the brackets pm curts he will sell you them he makes them and everybody ive heard like them
^ Like hell they are! K5’s are only quieter because when compared to the same size air line, they aren’t getting enough air. If you have a k5, you need larger than a 1/2" OD line. I run a 5/8" ID, and they are quit a bit louder than my k3’s.
OP- It really boils down to what sound you like. I personally love the higher pitch slap in face chirp that a k5 american tune has. The difference in the “H” and “L”, is just a high or low mount. The “A” signifies an American tune. For instance. My horn is a K5HA. K = K series. 5 = 5 chime. H = high mount, and A = American tune.