Can't help with the tang sight,never used one and it looks like it would get in the way.
On my 336, I put a Williams FP peep sight with the disc removed, and a front fire sight with no hood, great combo, and very fast. You can see the fire sight before your target in low light. The only thing better in real low light is a low power scope.
With the Williams FP, you will probably need to put in a taller front sight, I think you need one about .450 high or whatever comes close to that, the .375 was too short on my 70's model.