Well, I just have the integra fronts with stock drum rear. In my case, yes if I slam the hell out of them they will MOST DEFINATELY lock up! You have to know how to use the pedal and it took me a little bit to get used to them as well. I have Powerslot rotors with Hawk HP Plus pads and MOTUL RBF600 fluid, my brakes are INSANE over stock, but you just gotta feel out the pedal(called threshold braking in racing terms).

Now, like I said I do not have the rears yet. So I dont know if that changes anything. Your front will always lock before the back and you do not have ABS so its going to lock up if you slam your brakes. Are they locking up under normal driving or only when you slam them down? try using a little less sudden force and see what happens, maybe you just need to get used to them still.