Dual cone seals d6

I have a d68u with some bearing problems. Would you convert to the dual cone seals or leave it with Bellow seals? I see dual cone seals are much cheaper than the 500$ Each, bellow seals from cat. Are there any special tools or parts needed To convert it or maybe it's not worth it.
The field mechanic thought the bellows were a lot more forgiving seal.
Or are aftermarket bellows ok?

Also one other thing I could use some input on is when the engine is idling it gallops or loups. Like the governor is not holding a steady rpm at wide open throttle it's good.
Just at lower idle. Any ideas?
Thanks

I would check the low idle. It is most likely set to low. It wears over time slowly lowering the idle speed. Bump it back up and the surge should go away.