if u wanna fix the back and are using blocks, try a setup where drivers side is 1" block and passengers is a 2" block, this may sound weird, but it works and doesnt harm how it rides.
I got my rims for 700$ through a friend.
I had that same problem when I first got my 4" drop done. I'm still using 4 inch blocks in the rear(on both sides) but what I did is re-arched the leaf springs on the right side till it raised the right side to the same hieght as the left side. good luck!
s-10 trucks sit 1" lower on the driver side from factory, or so ive been told. you dont notice it until the truck is lowered. you can just go and get a spring pad or spacer. it is a rubber ring that sits under the coil to lift it up an inch. my 84 s10 was noticeable after i lowered it with all belltec stuff, but i didnt know about the 1"thing until recently. my 97 sonoma at stock height is about 1/2 to 3/4" difference from driverside to pass.
i heard once that s10 sit 1 inch lower on the drivers side i believe. i also read that bell tech was the only company that took that into consideration when designing there coils. you might have the coils on the wrong side of the truck. i had a 97 s10 and i noticed it because i used chassistech coils and they didnt compensate for the inch difference.
belltch makes a spring spacer for the lean. they do not make the coils different for one side.
the spacer is p/n 4930 it goes in on top of the drivers side coil. will lift it about 1/2 to 3/4 of a inch.