Lone Racer

I just recently ordered a set of 20mm alloy shocks for my buggy and a bit confused on what length springs I need. I have found 90mm and 100mm for the rears along with 50mm and 60mm for the fronts. And the silver springs that are on my old red shocks are 120mm in the rear and 80mm in da front. Needless to say, I'm lost and have ordered wrong parts before. Can someone please help me out here. Thanks