Clicking sound

Hey everyone, it's been a while since I posted here. I just got my dart running again and noticed a clicking sound comming from the engine. My dad (who knows a lot more then I do) said that it was probibly the lifters and that they might need to be adjusted. I just wanted to get the opinion of you guys on here on what it could be and if it is just the lifters is it ok to drive without causing damage? Thanks.