Getting ready to replace my valves and have a question. If the valve guides that are in the head currently are in good shape do I need to replace them if I am going to stainless steel valves? Do I need to replace the springs or can I just do the valves. I am on a budget like most people and trying to keep my cost down, however don't want to half ass this and have it bite me later. Any and all advice is appreciated. Thanks.