? bout lowering blocks

Is there really any difference between a 3' lowering block and a 4' pinion angled lowering block far as makeing my truck sit lower?
My truck is Notched and has a bridge wit mono leaf, i plan on 4 linking it in the next few months! I was just wondering rather i should bother changin my 3' block to the 4'..thanks

any 1????

it will get you an inch lower thats it

thank u

go with the 3'' it will save you alot of problems in the future. this is how low the u bolts sit with a 3'' block