add a leaf kits

Whats the difference between the long and short add a leaf kits?  Whats the best?

Short add a leafs are cheaper... they go under the leaf pack.  They're also a bit stiffer than the long add a leafs.
 
I'd recommend long add a leafs.  They're a bit more work to install, because they go between the top two leafs in the pack, but they distribute the load over a larger area on the spring pack, and aren't as rough on the ride.

yup jigg's right. I just installed the long add-a-leafs. The shorts are known to give a real bumpy ride. The longs were actually cheaper. only by about 10 bucks though. They gave me just the amount of lift I was looking for. Go for it.
 

how high should the back of a 2000 2dr blazer be? i think mine has sagged a little. which long add a leaf do you recommend and what is involved in the installation?

add a leafs will work even though the spring pack is under the axle