4WD have usually a 2" block in the rear, 2WD only have a 1" that I've seen, sometimes a 2" if they have a really soft spring back there. Also the coils used up front are slightly taller, and also slightly stiffer.

 

I looked at a bunch of frontends in the junkyard and since the I-beams are different, but simular (if that makes sense!) it is hard to see the difference. Stiffer springs is really hard to see , but it makes sense when coupled with the slightly taller spring and I-beams.

I didn't look at the rears since I don't think I have a problem there, but good info that that I'm sure will come in handy someday!

Thanks guys.