I think you mean the FK4- series make more torque... not all FK cams are created equal. and yes in general the FK4- series deliver more torque within the engle range. but fast ramps also create greater strain on the lifter bores. on my engine I bushed the lifter bores. no issues since.
You're right, I did mean the 4x series.
I've bought the JN5. We'll see how it dynos.