[Dirty Harry]

BrandX, the lifters are stock-style hydraulic Edelbrock units.

Thanks for weighing in, Wbulk. I figured the shouldered stud meant to torque 'em down, but I couldn't have the valves hanging open. I just had new exhaust valves and seats installed. I know the heads have been milled twice just since I've had them-just enough to clean them up, mostly. Maybe I should expect this with 44 year old heads. I suppose I need to check the geometry and see if shorter pushrods are indicated.