So the head pic sort of tells a tale of its own. First, the gasket isn't a gasket, it looks more like someone didn't have the gasket and tried to go fancy with a generous and sloppy bead of orange RTV. Further down the rail you can see a split in the bead.
That aside, those are stock rockers, sitting on pressed in studs, with no pinning to secure the stud from pulling. The springs and collars ought to be bare metal and only show a layer of good clean oil. The third from the left rocker is about the cleanest of the lot. For the rest, well to me they typify a head that has not seen many oil changes in recent memory. The crud and scunge clinging to those rockers is something like barnacles on a boat hull. They are the build up that happens when an owner just puts gas in the tank and blows off any other major maintenance or service, or only does it when absolutely necessary. You saying this motor came from another donor vehicle would make sense if the donor was some kind of service truck that spent a lot of time idling and only going for short, stop and go excursions like service calls. Company owners come in two general flavors, the ones who understand the importance of keeping their fleet vehicles in good working order and maintain service records and call in schedules for grease/oil/filters, etc, and the ones who buy trucks and cars and just drive them. No service, little maintenance, run them to death and dump them for cheap. Use them for a tax write-off and amortize the value over time.
As for the tick, it was almost a holy writ that first gen small blocks came from the factory with a tick, usually in the lifters. It was not a sign of problems, it was just, how do I put this, a built in idiosyncrasy that seemed chronic. Quick anecdote here, had a cousin with a brand new 70 Nova. Beautiful car, well kept and maintained, but he got rid of it as fast as he could. Why?, NO tick. In and out of the shop ??? number of time, no one could figure out why it didn't have that tick and it didn't run worth a S***. It was a lemon. So.
Much as I hate to put this suggestion on the table, what I see for your motor is a session on the engine stand. There are too many questions about the health and life of this motor to go the band-aid and bandage route. The crud visible in the head shot is a symptom; it points to similar build up and crustification deeper in the mill. Pulling the intake would probably reveal a nasty accumulation of the burnt crispy crunchies clinging to the valley surfaces and drooling all over the lifters and pushrods.
Summarily, throwing a cam at a motor that possesses the potential for needing a rebuild is not a good use of your project budget.