I have a 1982 AMC Concord 258 cu. in.I am having a noise on startup and running that seems to be like a clacking sound.It sounds pretty loud.I have heard a light ticking before when the car was run regularly but it sat up for a month or two and was not started.I had it before but only lightly.The car sat up a while and now on startup it is worse than ever.I changed the oil and put some Risolone with the new oil.It was less noise before I changed the oil.Do you think it could be lifters or rocker arms?It is hard to pinpoint where the noise is coming from.