[DeTomaso] Techno Question: 543 Chart for a 351C??

[Charles Engles]

Dear Forum,


                   I have been told in the course of my amateur engine adventures by an old mechanic that a "543 Chart" would be helpful and that there is one for a 351C.    

                   What is a "543 Chart"?    What is it good for?    Is there one for every engine?


                                   Curious,  Chuck Engles