why kind of truck are you talking about? i'm assuming that its that 86-87 chevy on your web page and i know what your talkin about kinda have the same problem mine is a 85 C10 that has real heavy suspension in the back but personally i like the rake stance but have a ton of steel in the back then it sits level but anyway looks like yours is a 2wd so its got the coils up front and they make spacers that strech the coils theres ones that just twist in and raise an 1" or ones that you spread apart with bolts like these on JC Whitney
Coil Spring Spacers i had a set of the twist in type in a 85 dodge omni in the back and it did raise it and ride quality didn't seem to change
Nate