SBI and Snyder both sell good seats, readily available through any parts warehouse. Local machine shop should have 'em. I like the smooth machine finish on the Snyders. S-I seats don't machine well, they are "stringy" when cut with a multi-angle cutter. They grind well though.
Ford sunk a lot of valve jobs right from the factory on the FE's. Lots of times, they are already at the max depth or past, before the first valve job. Exh is easy to correct, as you're installing new seats. Intakes, first try oversize valves, like a 2.15". We use these quite often. But, there are times, especially on CJ heads, that even the 2.15 valve won't help. You either have a sunk valve and have to cut a lot off of the tip of the valve, or you install intake seats. As a last resort, we have installed intake seats on FE heads for years with no problems.
But: you must use sharp, good quality cutters to ensure accurate size seat cuts. AND, you must always install the intake seats FIRST, exh seats second. Heat the heads before install. Two burner plate heater works well. Always measure your seat rings to catch any that are slightly out of spec. Make sure the seat rings are beveled on the outer edge. Any quality ring will be. Have fun.
