I would imagine the majority of cams going into old muscle cars and bracket cars are still flat tappet cams. I make sure my lifters spin in the bores, removed the inner spring and reved it between 2,500 to 3k for 25 min then change oil and filter. Then the next day I do another short 15 min break in change oil and filter. Then I'll drive it for a short trip or two with some idling before installing the inner spring.