You're gonna look mighty funny driving down the road with a 65" wide rear and 60" front, not to mention turning will suck. If you're gonna swap axles, swap both front and rear at the same time. And even here I'll say it, DO YOUR RESEARCH. We aren't here to talk you through every step of this. A dana 60 is a big axle, bordering on major overkill for 35" tires. If you don't plan to go bigger than 35's ever, look into an 8.8 or something.
The mountains are calling and I must go.