Timothy Morphy

My engines(95 RA) started knocking,mostley at lower reves.It comes and goes,but is there more often than not. It's louder under the car,and sounds like it's from the passenger front head.
I was wondering what the difference in sound was like between head and block knock? Is it possible the water pump's knocking(it was making a dry bearing noise the other day)
Does anyone know a good garage near luton?

Thanks,Tim