OK guys I have a 1978 f150 with a 400 in it. I am going to install a new cam and lifters as well springs locks and retainers. I have read online that in 1978 the valve stem locks and retainers are different sizes. I am not talking about the springs because of the rotators. What I am wondering is if all my valves (exhaust and intake)will accept the same size retainers and the same type and size stem locks.