2000 dodge durango timing

i recently bought a vehicle that needs worked on previous owner worked on the head putting a new headgasket and screwed the timing they had it running but when they give it gas it quit i have looked at it but cant see no timing marks on the head they are two dots on there only is the dots what i use to time it with also its got a 4.7 liter

timing is computer controlled and non adjustable.take covers off and check marks.get a subscription to alldatadiy.

the head is out of adjustment on timing the person that worked on it did put it on top dead center but some how he said the cam rolled when he took it off and he tried his best to put it back the way it looked and he got it started but it wouldnt taken any gas but he said it would idle but given it gas it would stall out he said he drove it until the headgasket blowed

ok i took the other valve pan cover off and put the motor top dead center the driver side head is at 12 o clock the passenger side head is at 5 o clock the cam lobes are numbered anybody can help me from here