You may not see much difference. While I did make some other slight changes to mine I went from a 4:88 to a 4:56 and so far it has stayed pretty close ET wise. I did have to play around with the shift point a bit to find the new sweet spot but I'm not sure if that was due to the new gear or the slightly bigger cam. (I went from a 525 hyd to a 555 sld with roughly the same dur.)

My is if you already have them, use them and if you find it doesn't like it it's not that tough to swap them out later.