[olddog]

Just considering the head, it is where the valve spring coils bind. I cannot remember the recommended minimum clearance, but with the valve fully open, you should be able to slide a feeler gauge between all coils. The tightest spot should be at least some number.

The clay measurement on the engine described above should always be checked.

Another alternative is to set a piston TDC. Set a head on with no valve springs on that cylinder. Then measure the valve travel from touching to closed. Both intake and exhaust. This will get the total clearance at TDC, provided the head is torqued down with the gasket that will be used. Then you have to know the cam lift at TDC. This method is good for choosing a cam, but I would still check it with clay before assembly.

After 60 years there is likely no such thing as a stock head. Ford made so many head changes over the development of the FE and with union issues I would not count on all heads of a casting number all having the same valves, springs, retainers, etc. Each head should be checked individually. There is likely no one number for maximum lift.