Google 52" front spring swap. Like mentioned above, the B52 kit from DIY4X is the bolt on easy way to use rear springs in the front of a chevy. You can also do it with the mounts on the front of your blazer frame. Just by busting out rivets and rearangeing the stock bracketry.
However, with your +2.5 52" springs it would net you around a 6"lift.
I removed my 4" rancho lift springs, and used the b52 kit and my truck sits the same height as with the 4" springs. Rides waaay better. Also moves the axle forward a bit. Not enough that you would see it though.
If this is a rig you plan to wheel offroad, all of the off the shelf lift springs will make you hate your life on the trail. 52s are widely used and cheap to find at local junk yards. And will flex, unlike any of the name brand lift springs.
For more info, look on pirate 4x4 and also there is some good info on CK5 forums too.
