Would C7AE-E be correct for 67 then, thanks. Its tough even with something like the intake to get accurate information. There's an older booklet some here may know called "The ford high performance parts identifier" written by Robert M. Winkelman from 1988 that lists all of the hipo engines and their major parts and for 390 GT 66-68 it calls for a C6AE-E cast iron Large "S" cast in area of casting number. My C7AE-E has a smaller S than the large S that I have seen but didn't pay attention to the casting numbers.