When you are on the lookout for a replacement underdash harness for your 1970 Mustang, be aware that there are several different ones that were produced depending on certain options, body types, and date of manufacture. Below is a list of those harnesses that were used.

Body Codes Harnesses 63A - Sportsroof Standard Interior 63B - Sportsroof Deluxe Interior 63C - Mach 1 76A - Convertible Standard Interior 65A - Coupe Standard Interior 65B - Coupe Deluxe Interior 65E - Grande 76B - Convertible Deluxe Interior - 63A,B,65,76 without AC without tach - 63A,B,65,76 without AC with tach before 11/1/69 - 63A,B,65,76,without AC with tach after 11/1/69 - 63A,B,65,76 with AC without tach before 11/1/69 - 63A,B,65,76,with AC without tach after 11/1/69 - 63C without tach before 11/1/69 - 63C without tach after 11/1/69 - 63C with tach before 11/1/69 - 63C with tach after 11/1/69