Oil pressure please help

Thanks everyone that's what I meant 20 idle and 30 going down the road I'm not sure how many actual miles I'm saving my money now for a crate engine I've got my eye on but it will take a while its in my 76 dart sport and it is an after market gauge with the 50 weight oil it don't quit knocking for like 10 min I put 10/30 in it and it quit knocking it doesn't ever use oil thanks for all the replies