need help installing new rearend

[blazer2007]

Well I got my donor ford 9 in. rear all cleaned up,brackets removed etc. so now I have a fresh start to do a 2 or 4 link setup with bags on my 78 blazer.Question is, where do I start with measurements.I would like to do as much on the bench as possible so I can use the truck rear as a guide for reference.Any posts or web sites would be nice.The reason I,m using the 9 in. is it close to the same width,has 5 on 5 bolt pattern and is a 4;11 posi and was a good deal.