Don't think stock springs will help. Tried to do this on my 86.. When I complained about sagging back in 91, thinking that the Toyota springs had sagged over time. I had Toyota replace the stock springs with stock ones and it still looked the same. (And no, this wasn't a warranty nor a TSB.) A couple of years ago I replaced the susp with Eibachs and Tokicos. It improved it a bit still sagged a little. I'm beginning to think that it was due to constant pounding on that side (driver weight plus sheet metal getting pounded).