Kyle,
I agree with Lazy JW. I don't think there is a reliable way to measure any spot on the head to get a thickness measurement.
I really think you'll want to cc the head. It is not hard to do at all. Get about a 20, 30, or 40 cc syringe at a drug store (I get mine at a horse stuff supply store) Should cost $1.00 to 1.50. No needle.
Get a piece of 3/16" or so plexiglass that is about 5" x 5" See if your hardware stores have a scrap left over from someone else. Call around.
Drill a 1/4" hole off-center in the Plexiglass - so when it is placed on the head the hole is close to being over the spark plug. Put a spark plug in the head. If the valves are out, set an intake and exhaust in place by putting a gob of Vaseline on the valve faces to seal them.
Put a film of vaseline on the head around the combustion chamber and tap the plastic into place with you fist.
Prop up the head at an angle so the hole is the highest point. Since I use a 20 cc syringe, I squirt in two full syringes and then slow down for the thrid load. When the fluid fills up to the top of the hole, I note how much fluid I have left in the syringe, and I WRITE IT DOWN.
A couple of tips. This can be messy - do it outside or someplace that can get wet.
David uses Auto tranny fluid - I use water with a couple of drops of dish soap in it (makes the water wetter) I think water cleans up easier.
Have paper towels and/or rags handy.
Don't pull the plate off with the cumbustion chamber full of fluid. Suck the fluid out with the syringe.
If you are working on a head with the valves installed, put some vaseline on the valves anyway to make Sure they don't leak.
After you cc them all, don't be surprised if the are different by a few cc. Ford wasn't spending any money for blueprinting.
Got to our web site and use the compression calulator to see where you at at and where you want to be.
Hope this helps
