Well I dissagree, but that's just me. I don't think it is A must do but I also dont think it would be a bad idea. I have run 1.9's and stock valve springs for some time with no problems.Call me lucky.What was the miliage on the cars with the broken springs? Just curiouse. I was at right around 106,000 when i took my stock springs and 1.9's off.