I know its bad to run different size tires on an awd vehicle, but can it hurt anything on a 4wd wagon? I have 3 185/70r13 tires and 2 175/70r13 tires.

Just don't use the 4wd when you have different tire sizes on. Different tire sizes = different rotation speeds + 4WD = severe drive-train binding that will break stuff.

FWD will be fine.

Ok cool, thank you. Im just gonna have to wait till I can find 1 more 185, ill be way too tempted to go out wheelin with these tires.

just make sure the same size tire is on the same axle