Highly Interchangeable (with caveats):
* Engines: Many engine parts, especially internal components (pistons, rods, crankshaft – *depending on the specific engine*), are interchangeable within the same engine family (e.g., all 289s, all 260s, etc.). However, external parts like manifolds, carburetors, and accessories often vary by year and option.
* Transmissions: Manual transmissions had some interchangeability between years, but automatic transmissions changed more significantly. Always verify specific transmission codes.
* Suspension Components: Many suspension parts like springs, shocks, control arms, and spindles were similar across the 1964-66 Mustangs, but there can be variations. Always double-check part numbers.
* Brakes: Brake components like calipers, drums, and master cylinders had some overlap between years but may not be a direct swap. Verify part numbers and specifications.
* Interior Parts: Some interior trim pieces, door panels, and seat parts may be interchangeable with later first-generation Mustangs (1965-66), but there are subtle differences.
* Electrical Parts: Many electrical components (wiring harnesses excluded), like lights, switches, and gauges, might be interchangeable with later first-gen Mustangs, but again, verify part numbers.
Less Interchangeable or Not Interchangeable:
* Body Panels: While some smaller parts might be similar, major body panels like fenders, hoods, doors, and quarter panels are generally *not* interchangeable with other years. Even within the 1964 model year, differences can exist.
* Wiring Harnesses: These are almost never directly interchangeable between years.
* Bumpers and Grille: These are very model-year specific and even slight variations exist within the 1964 model year.
Important Considerations:
* Part Numbers: Always use the correct part numbers when ordering replacement parts to ensure proper fitment. A reputable Mustang parts supplier can be invaluable here.
* Model Year Variations: Even within the 1964 model year, there were production changes that affected parts. Knowing the exact month of manufacture of your Mustang helps.
* Specific Options: Options like power steering, power brakes, air conditioning, and different engine types significantly impact part interchangeability.
In short, while some parts might *seem* similar between a 1964 Mustang and other first-generation Mustangs, always verify compatibility before purchasing and installing. Using a parts catalog specific to your 1964 Mustang is the best way to ensure you're getting the correct part.
