can someone please explain which OME part numbers are for which spring?

example:

part # 0123456 - 2" light duty
part # 7891011 - 3" heavy duty

i know there are 4 different OME spring options for us right? and i'm trying to put together a lift...i want to run a 285/75/16 on my stock wheels with 1.25" spacers so i need 3" right?

i am dead set on that tire size because i want to go with bfg km2's. i know im gonna have traction and driveshaft issues so i am still researching that. the only thing i'm concerned with in this thread are springs

thanks guys!

 

http://www.expeditionexchange.com/ome/indexsprings.php