Ford has sold more than nine million Mustangs since the car’s April 17, 1964 debut, and over time many of the surviving 1965-73 Mustangs have been modified from their as-built specification. Fortunately for owners who wish to know exactly how their cars came from the factory, there are several resources for looking into a car’s past.
When needs go beyond visual cues – for instance, a 1969 Boss 302 will not have the quarter panel scoops that other Mustangs carried – there are many publications and sources for determining Mustang factory specs and matching parts numbers.
The most-utilized and viable guides come from the work of Kevin Marti, a licensee to Ford Motor Company’s entire production database for the 1967-2007 model years. His records have made Marti Reports – detailed accounts of an individual car’s original equipment – an essential link in verifying a claim of matching numbers. Marti has also published “The Mustang and Cougar Tagbook,” which provides decoding information for data plates, body tags, engines, transmissions and carburetors for 1965-73 models. Marti’s “Mustang by the Numbers” contains production facts on Ford vehicles and over 12,000 statistics for the 1967-73 model years.
The 1965-69 models have a metal door data (or warranty) plate, which changed to a Mylar vehicle certification label for 1970-73. The data plate includes codes for the body style, exterior color, interior trim, scheduled build date, transmission and axle ratio. The VIN on the door plate should match the VIN stamped into the driver’s side inner fender apron, and it should also match the windshield VIN tag on 1968-73 models. Experts can spot whether or not a data plate has been replaced by checking the rivets.
Matching an engine to 1965-67 Mustangs can be a bit more challenging due to the lack of engine and transmission tags, with the exception of the 289 Hi-Po model, but it is still possible to find out which engine a car should have via the engine code listed the VIN. Thankfully, that difficulty was realized and Federal law began requiring the stamping of VIN numbers on engines and transmissions beginning in 1968. And since the VIN includes the engine code, a quick check for a matching numbers engine can be simple.
For example, a 1966 Mustang with a later 302-cid Windsor V-8 engine would not be a matching numbers vehicle. But just because an engine is missing a tag, or the numbers are unreadable, doesn’t necessarily mean that the Mustang is not a numbers-matching car; it could be that the engine had machine work when it was rebuilt or that the engine stamp wasn’t aligned properly at the factory. Complicating things further, door tags are often removed or painted over during restoration.
If you want to dig deeper into the matching-numbers realm, casting or engineering numbers are another way of identifying factory parts, and nearly every component, even a headlight housing, can be equipped with a tag or stamped number. While the correct casting number on a part doesn't prove that it came with the car from the assembly plant, it can at least verify that it is correct for the year and model of car.