I have the Most Wanted Expansion and want to fly Y-wing and Z-95 in my squad, but can I use my Scum dials in a rebel build in tournements? As far as I have read the rules, and tournement rules there is nothing preventing it. I am not interested in opinions, but if anyone can tell me where if any place, that FFG has stated, that I cant.

I think it's in the tournament rules somewhere but I don't remember for sure. I do know for certain though that IS allowed. The pilot cards and and the cardboard tokens on the bases have to be the correct faction but the dials and models do not.

Go to the X-Wing products page here on the FFG site and scroll to the bottom. You will find Tournament resources and FAQ's and such.

Here is the link:

x-wing_tournament_regulations_v22.pdf

The specific rule is at the start of page 4.