So I'm currently in the process of having my Sr rebuilt and I'm putting bc valve springs in whilst being rebuilt as I'm planning on getting cams later down te line! Putting these springs in will I need to upgrade the retainers as well or are the standar units good enough to use? Was thinking something like tomei pon cams or maybe the Brian crower cams that conceptua offer at a good price! Any advice would be great on this or other things I might have missed to run cams