intron

Hi i was wondering if i replace the guide pulley on my RD if i can use a shimano centuron pulley, the one that has some lateral play?, the old stock one does not seem to have the play it is a 1984 Shimano ex RD with friction shifting. The teeth on the old and centuron pulley are 10t. It is on a six speed. is the new pulley too thin? will this improve or degrade shifting? Has anone tried this. Again the teeth count match, but the old one does not have the "play" as the new one. So, please any help would be greatly valued.

Thanks