There's a lot of info on here about this that a search would provide. I'm not the type to bash, so I will tell you that after doing three so far it has become easy for me. The last one I did I had u-bolts made at a local spring shop, I used u-bolt plates from a Ranger, and reused the mounts that I cut off of the 8.8. I also reused the YJ shock tabs that I cut from the D35 housing and parking brake cables by cutting them and using cable crimp ends that you can get from any good garage door company. As for the spacers, they would be 3/8" and completely unnecessary unless you are running the stock wheel offset. You'll need a flange from an Explorer/Ranger to connect the drive shaft to the 8.8, and you may or may not need a 1310 to 1330 universal joint depending on what year YJ you have. Don't forget to weld the axle tubes to the housing with hi-nickel rod.
Mine - 89 YJ Hardtop, 4.6 Stroker, AX15, Bored TB, TB Spacer, 23# Injectors, 8.8, 4.88's, 33's on a Rusty's 4" lift - Currently being built from the ground up :)
Wife's - 94 YJ Hardtop, 4.6 Stroker, AX15, Bored TB, TB Spacer, 23# Injectors, 8.8, 4.88's, 33's on a Rusty's 4" lift.
Spare - 91 YJ Hardtop, 4.0, AX15, 4.10's, 4" lift - Currently under construction........
Yes.......I have a Jeep addiction.........