Can I add 1-2 inch coil spring spacers and shackles onto a rough country 4.5 inch lift?

 

As long as going to 6.5 won't cause a problem with anything else yes.

 

Question is, why? The more you lift, the more things you have to modify. I think 4.5 inches of lift is just about perfect. But plan on longer shocks, sye if you don't have one already, longer brake lines, adjustable control arms if you don't have them already and so on

 

Don't forget longer shocks and longer brake lines.

 

The control arms will hit the shock mount too.

 

Same why are you wanting to, perhaps to run 38-40" tires or something. That way would work for a "Mall Crawler" but for a off road rig that would not be the best of ideas to go that high, plus all the money involved either way.