Rough country leveling coils + coil spacers?

[Clumzi]

So the back end has 2" shackles, brand new leaf springs and coilover shocks. Front just has the Rough Country leveling coils (1.5" I believe). Would I do any harm adding something like these....

http://www.summitracing.com/parts/sps-1819/overview/year/1991/make/ford/model/ranger

What's with the note on this about? "When installed in front, car height is raised approximately 2-1/2 to 3 times spacer thickness."

Are they saying a 1" spacer adds 3" of height? How?

Would I need to get the truck realigned?

 

[Exenos]

You would need to get the truck aligned. The spacer height thing is really only applicable with normal a arm ifs. With the ford twin I beam a 1" spacer will net you something like a 1 1/4 lift( I think) because the pivot point for the arm is so much farther away than with a normal ifs. Instead of buying a coil spacer, just use a washer stack, its cheaper and just as reliable or more reliable than a spacer.