Replace all four with the Foxes, unless you have money to burn, stick to the Foxes, if you don't, you replace the fronts you will quickly learn how bad the rears are. If you don't have the funds for all four, you can do the spring spacers, that you have to make out of 1.5 inch black pipe, I don't know the length, there is a thread here that covers that, but you will still have stock crapy valving, but will relieve the whaming. Fox's are the way to go on a limited budget, Walker Evans, 814's and Elkas, if you have an unlimited budget ( Elkas ) will be the cure . I've got the Elka Stage 5's and love them, don't have an unlimited budget either, but I like to tinker. So that way was the best way for me. I would go Fox's. Have fun and be safe!