Speedldew

So, during cleaning I just lost one of the bushings for one of my pulley wheels on the porch under my balcony. Hopefully I gonna catch it tomorrow if the company which sits there lets me get out of one of their windows. Well, luckily, in the meantime I could cannibalize one from an old 8x Deore derailleur and it seems to be the right size and it shifts well.
So first question: Is there an actual difference between 8x and 10x pulley wheels in terms of dimensions or are those compatible without any caviats?
Second question: This made me think that might as well buy new/better ones. Do I have to keep anything in mind in terms of compatibility apart from them being 11teeth and generally for Shimano?
Also, any good recommendations for good bang for the buck pulley wheels? Thanks!

Correction: The Rear Derailleur where I got the replacement bushing from was actually a Deore 9x Derailleur.

redlude97

Generally the widths are the same. The thing to watch for is the number of teeth on the pulley which changes the diameter and possibly affects capacity and clearance issues.