more inches on my dually..

[wwj75c30]

So i want to get some more inches on the front on my 75 c30 while i keep it a 2wd i already have 2 1/2" coil spacers up front and i want it up to 4" susp and ill do a 3" bl. can i get any lift springs and add my spacers? i know for a 1/2 ton you use 1ton bbc springs. can i get heavier springs or lift springs? if i have to ill double stack spacers or something. anyone got any ideas? i need help and opinions. and no i dont wanna hear it needs to be lowered cuz its 2wd. so any lift help apprciated thanks