The D35 takes shims on the outside of the bearings. Pressthem on first. On a lot of gear sets, there will be numbers on the end of the pinion shaft etched on there. May look like +.001 or -.003.
If the new set is within .005 +or - from the original set, shim the pinion exactly the same as the original. Some gears like precision gear have a pinion depth measurement marked on there. It takes a special tool to measure this. Start with the same shims and check your pattern. Adjusting pinion depth will also affect backlash, so you'll have to adjust these at the same time. D35 backlash should be between .005 and .008. Checking backlash requires the use of a dial indicator, usually with a magnetic base. Remember what Satan said about heat, noise, etc. In most cases, improperly set up gears won't last 1000 miles. I think the cost to have a shop set your gears is around $225.00. Kind of pricey, but when you have to buy the gears all over again, it negates most of the cost.
Do it right the first time.
HTH, Dan