if i go with the rc 2 inch shackle lift . will i get a full 2 inches of lift?

 

Sorry, no. The geometry / triangulation of lift at the shackle, (tail end of your spring), 2" there will net you about 7/8" at the axle. Try your jack and a tape measure. Jack at back, up 2", measure the change above your axle. Still a good way to net some lift and flexibility.