I don't think that I would be very comferdable going with 35 inch tires on stock D30/35, you are asking for trouble. If in fact you do use those tire you are for sure going to want to regear. I would say 4.88 for sure, you can't go any higer with those axels, but swapping both front and rear is a pretty big expence. It would be a shame to spend that much money on an axel and then break it two months later with a 35inch tire. Throwing money at stock axels is really like throwing good money after bad.