Has anyone used Ford Performance's stainless-steel valves, specifically M-6507-J302 (I) and M-6505-G302 (E)? Both have OAL of 5.078, 11/32 stems, .385 tips, and single, square-groove? The intakes are 1.94 and exhaust 1.54. I recall reading they are made in Argentina, as many/most valves now are.