If all goes right I will be picking up a set of 3/4 to axles this weekend. Hope to install them in a couple of weeks. I have searched and found some good infomation but still have questions. My first question. Will I need backing plates for the front d44 and spring plates for the back 14 bolt? What are backing plates and spring plates? I read their are lower and top spring plates. Which will I need? The axles will be going in my 89 k5. They 3/4 tons are coming out of an 80's truck. I know I will need a ujoint #447 to replace the back 10 bolt ujoint. Anything else? Sorry if these are dumb questions.