Thanks to ponyboy for hooking it up with the 4" Wico Balltops.
I got the light blue balltops and dyed them black with Rit Dye. They came out VERY good. I used the black liquid Rit Dye and poured half the bottle into a small pot with enough water added to cover the balltops. The dye does not dye the metal. It leaves a film on the chrome, but it just wipes right off. I just used some fishing line and hung them so they were not touching the bottom of the pot, but the balltops were completely covered. In about 5 minutes of boiling they were as dark as they were going to get. Then just rinsed them off with cool water and they were good to go. They came out so good they look like they were originally black balltops.
Here are some pics of the two shafts side by side and with a ruler. The Wico shaft dropped right into my joystick and no spacers (washers) were needed at all, perfect fit in every way. My CP is recessed from underneath for the P360's though, so I'm not sure if that is why I didn't need spacers and I've read that others did. The only problem is that the P360 dust washers are too big for the wico's. Not too bad, but it is noticeable.
Overall I love the Wico balltops in my P360's, they just feel better all the way around.