Sears also sold "rebuilt" flathead Ford V8 short blocks. From what I was told those were to be avoided completely. Valves were the main problem. I know valve work on flatheads was not what most mechanics lived for, but it wasn't all that bad if the engine was out of the vehicle. However I suppose from a rebuilder's point of view it was one of those time consuming things that ate into profit.
Around 1970 I bought from JC Whitney a set of adjustable flathead tappets. Pretty neat idea, really. Each one had a hardened bolt at the top and you just adjusted the clearance and then locked it with a separate screw.
