I dont think there is a 1" shackle. What you can do though, is get a 1" lowering block from ebay 2-3-4 Lowering Kit 4x4 S10 S15 BLAZER SONOMA JIMMY S-10 | eBay

that would give you a bit less rear end hight, with the added weight load. I know thats 2", but see if there's a 1"

-OSS

 

a 2 inch shackle gives 1 in o lift im still really shocked your add a leaf made your blazer lift that much

 

get torsion bar keys.
should bring your front up nicely without a ridiculous crank to your torsion bars.