You need to reassemble it. Get a dial indicator and compare the amount of lift at the spring retainer from one to another. That will tell you if the cam is shot.
Good luck getting an accurate read on that with squishy hyd lifters and full spring loads.
Are you sure the marks on the pushrods are from the most recent usage, or could they have been there before?
At this point, since you’re not using OE heads where you could access the lifters without any further disassembly, if you really want to know the condition of the cam and lifters........ you’re probably going to have to pull the intake for a look see.
The other alternative, if you find the filter is clean........ is run it some more and see if you can isolate where the noise is coming from.
