correct wheel spacer to put 4wd wheel on 2wd
 

I just picked up 4 1999 4wd wheels to replace the stock base model rims on my 1999 2wd 2dr blazer. Obviously the backspacing is wrong, and I've been searching and searching the web and can't find the exact answer I'm looking for.
Most posts are from people wanting to extend their wheels out a little further, I'm just looking to make the 4wd wheels mount on my 2wd truck and sit as if they were stock wheels. I think the 4wd rims have around a 6" backspacing while my 2wd are around 4", does this mean I simply need a 2" wheel spacer?
And is this conversion going to be SAFE? This is strictly a street truck, but I do alot of highway traveling. I'm going to go with Hub-Centric spacers

Help please:icon_hyper:

You are correct, 2" spacers would push the 4WD wheels out so they fit like your current wheels.

As long as you get hubcentric spacers and torque everything properly, everything should be fine. I know there are plenty of people who use spacers offroad that don't seem to have any problems