3/4 ton springs vs 1 ton springs

[84chevy4x4]

Ok heres the deal. Im running an 84 chevy 3/4 ton 4x4 and it had the original 3/4 ton springs under the rear end with a 4" lift block. Both stacks of springs had some busted leafs so i scrapped an old 1 ton c30 chevy and took the springs out of it. I took the correct leafs out of the 1 ton stack and matched them to my original ones and threw them under my truck. I set the bed on the frame and it looks like it has way more then 4 inches of lift. My question is do the 1 ton leafs have a higher spring rate or whatever? The picture is with only a 4 inch block out back abd some 4 inch springs up front.