tires and full-time 4wd

I'm getting a set of used tires from my brother-in-law... they are all 30x9.5, but the front two are different from the back two. They have a similar tread pattern with almost the same amount of miles on them.

Does anyone know if this will cause an issue with my full-time 4wd? I've read that all four tires must "match". Is this close enough?

Thanks!

the 242 won't care that much.

if it's difficult to shift back into 2wd, then they're too different.