Help me get my slant running right

thanks all for the input! i'm going to take a look at it in a couple days, hopefully. I forgot to mention, the compression is 120-130..... i'm pretty sure it's not the vac advance but will check it.... it's points. I'm pretty sure it's the original motor so it's mechanical lifters, right, 1970? i was told by the PO that the PPO had adjusted the valves.... maybe he got them too tight..... hopefully it's the valve adjustment and not the T-chain.... thanks again for the insight ...