[Yukon Jack]

What is your intended use? If you're going to be doing a lot of offroad driving/more hardcore you may benefit from springs front and rear but for lots of people blocks in the rear is just fine.

I've used Tuff Country on my 69K20 and like it - be sure to check out Offroad Design's website as they have good products and great service.

Do you have the closed knuckle Dana 44 up front? If so you'll need an adjustable drag link to correct your steering. I don't think anyone makes a raised steering arm for the closed knuckle front axle.