Quote Originally Posted by roncova
Sorry, you're right. I had been using the wrong nomenclature. I have a L7 valve that was stock on my gun, and just bought a used X Valve. It appears that the old on/off assembly will not work, because the slot for it in the X Valve is threaded, and slightly narrower.
The on-off assembly sizes are the same for classic or xvalve/retro valves. Only the pins and assembly internals are different. Except for the way they work, they are interchangeable size-wise.