I know this has been discussed someplace, but I usually have bad luck searching for threads. I have a P4876348 380hp cam (288/292 and .501/.513) that I want to stick in a magnum. The mopar book recommends the 5249464 spring. I thought I read somewhere in here that their two spring offerings were marginal. Should I step up to the 4876062 heavier spring. Are the retainers recommended for these two springs the stock ones that I already have? I am trying to keep things simple.