15x10 on Duster

Im going thru the same thing you are. Im using 15x8 rims and want to switch to a 15x10 to get more tread on the ground. Not sure what rear I have,im assuming I have a A-Body rear. With the 15x8 rim and 28x11.5 QTP's my tire rubbed the leaf a little so I put on 3/8 or 7/16 wheel spacer and it solved the problem.
I dont want to use the wheel spacers so Im trying to find out what bs I need with the 15x10 rims.
Let me know what you come up with.