kind of off topic but i did one of those 340 318 cam swaps when i was younger same thing thought it would be a lumpy cam but it ran nice and strong . i then changed the heads to a milled 360 head bigger valves and at least a point in comp , then the little motor really picked up its feet.
i also do breakins on cams but its not just for the cam after having the engine aparts its good to run it and look for leaks and time it etc.