18's with 275s on a Duster

I've read soo many threads its mind numbing but, with that said. Stock 73 Duster Disc Brakes up front and A body rear Rear axle currently.
18x9 with a +35 Offset for 275/35/18 fronts
18x9 with a +35 offset For 275/40/18 Rear

I'm thinking ill need a spacer in the front but wasn't sure yet.

Can someone confirm my thinking?