My 336 only has holes on the side, and a dovetail front sight that (I assume) can be drifted out in my shop press. It sounds like the FP36/94 is what I'm after, for this one.
But I'm more interested in getting one mounted to my .500 HandiRifle. It hasn't come in yet, so I don't know if/where the mounting hole are, and how they're spaced. I'm hoping I can use the FP336 on it. I'd rather not have to tap holes in it.