Just did my rears with the $25 eBay spacers this afternoon. Leveled out the Viking real nice. Brought the bottom, of the rear frame, from 11" to 13". So it does 2" as advertised. I used the strap method with 4 straps, once I figured it out, it took me 30 mins from start to finish. It's easier to pull the tire off to do the job, but probably not necessary. Think it was a 15mm socket snd 14mm box wrench that I used. Those straps can be found at lowes for $7/ea.
I installed the spacers on the rear only and i"m setting at 13.5", my rear springs have stopped falling ( I hope) I have a lift kit with the front set at 2" and the rear sets at 3", with the spacers I'm setting at 13.5 on the rear and 13" on the front.