lift blocks or new springs?

[Jason71k10]

Just wondering if you guys have had any bad experiences with lift blocks on your rear springs?? My springs are fine, so i figured i could save some money by going with blocks and just put new springs on the front.
it's a 71 4x4

I know this would better suit the 4x4 forum, but they don't seem to get much response when posted there........Any thoughts??

thanks