Car Project: 1976 Cadillac Eldorado Convertible, Part 1: Retrofit Ideas

Surprisingly, I found more retail parts support for the 1976 Eldorado than I did for the 1979 Mark V. The Eldorado has the benefit of a convertible option, too. A common issue I noticed with these ’70s cars has been converting the tire code, after searching for the original code, into something modern. This Eldorado’s tire code was “L78-15” that is now 235/75R15 and that is borderline light truck tire territory. And a further note: the 1976 Eldorado’s tires were slightly wider than the 1979 Mark V’s.


  • Full-Size Luxury Car / Personal Luxury Car / Heavy-Duty Luxury Cruiser / Land Yacht Supreme


  • The Convertible, that was last built in this generation in 1976.
  • Not a brown one or a green one.


  • 8.2 L V8 x 1
  • Ideally, a modern V8 with the same or more HP and torque but lighter, smaller, that sips fuel and is relatively low on emissions.


  • Wagner – ThermoQuiet or better


  • Battery -> Group 78 AGM


  • Shocks -> KYB – Gas-A-Just


  • Tires -> MotoMaster AWII – 235/75R15 XL 109T


  1. Speakers (Front Door) -> Pioneer – 6.5″ x 2
  2. Speakers (Rear Seat Side Panel) -> Pioneer – 6.5″ x 2
  3. Speakers (Dash Corner) -> Rockford Fosgate Punch P132 – 3.5″ x 2