I bolt mine directly to the factory spring hangers and I have no issues at all. I have thought about the 002,003 springs but with my car weight I would think the rear would sag very quickly given the reputation of the current MP SS springs. The 454,455 springs have a very stiff front segment which is what you want under a stick car with some decent low end grunt Gus
64 Plymouth Savoy 493 Indy EZ's by Nick at Compu-Flow 5-Speed Richmond faceplate Liberty box Dana 60