I know in some cases on the s-10's (DIFFERENT CHASSIS BUT FOLLOW ME) when you lower the vehicle and changing the suspension geometry in general you will get a "lean" like you are describing. Normally we (s-10 aka baby gm's) add a poly spacer in the spring. I have seen the "chevy lean" on the s-series and sometimes just something small like an upper control arm change. But also, my 90 blazer with a 3/3 drop never had the lean to one side but others with same stuff did. It might be hit or miss.
Do like Gerald said and change sides. hell could you have a spring upside down? Welded the relocation bracket maybe differently? I am not familiar with you f-body guys rear end stuff, you guys usually pull away so fast that I do not have time to check it out
