Timing questions

So I got my 383 original 2bbl with .484 purple cam 750 holley had heads done with new springs and headers. so a friend of mine said you just rotate the distributer to the spot were it runs best... my question is I know there's more to it and have been reading about it but wonder is ther no specific # to have your timing at? Because it seems past the timing marks on timing cover like maybe runs 20 ish advanced but what should the total timing be and have read about making the mechanical weights open up sooner like changing springs or you can buy plates to put in distributer to limit the total. My dart has nuts don't get me wrong but I like to learn and do things right. Thanks