If it is a true K-B motor then it already has 10 to 1 CR. The K-B head on a 3K motor should give 10.7.
So how do you tell if it is a true K-B - check the inlet manifold face on the head to verify if there is a water hole to the inlet manifold, should be below no 4 inlet port.
Look after the gasket as I imagine they might be hard to get these days.
The other differences that you might explore - the lighter K-B flywheel and the K-B camshaft with the extra 10 degrees duration, an 18/58 vs 16/50.