Ideas on what's causing my click/tick/rattle noise?

Photo of valve guide seals
Left: Positive valve stem seal
Center: example of the 'Premium valve stem seal' included with a NOS FEL PRO full engine gasket set. Unfortunately, the packet does not have a part number on them. In my spare parts stash I did find a packet of the same style valve stem seals from Victor Reinz, part number B45623.
Right: Umbrella valve stem seal

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also on the subject of stem seals, I believe that Killer6 is correct in post #174 that the 'improved stem seals' were used in the mid 70's and that there are modern positive stem seals that will fit a mopar 1/2 inch guild.

concerning oil pumps my FSM has the rotor thickness limits listed below
1968 Mechanical valve trail pump rotor .649 minimum
1983 Hydraulic valve train pump rotor .825 minimum

the use of the word 'coking' is used to describe the residue that remains on an engine component when engine oil has severe oxidation and breaks down.
Since the intake valves in your motor have a black residue on the stem side it is a good assumption that the valve stem seals are leaking. The leak shows on the intake side as that side sees a vacuum and will pull oil in. The exhaust side maybe just as bad but that side sees pressure and will push oil out.
The leak may be causes by defective seals, or worn - out of round valve guide ID's, or worn - out of round valve stems, or a combination of all three.