Personally the Christ book is OK but I've found errors time after time. I like it for a basis of what to look for,
Just yeaterday I wanted to find the various FE & FT crankshaft casting #. It did verify what I wanted. Also wanted the C7TE and 3U codes as well as std. measurements.
I use it as a very basic reference. For more exact FE info I've got both Barry's and Jay's book.
Richard