429 Engine Specifications

• Between 1968 and 1973, Ford produced three different 429 engines, all with eight cylinders. These were the 429 Thunder Jet, the 429 Cobra Jet and the 429 Super Cobra Jet. The 429 Thunder Jet had a power output of 370 horsepower at 5.400 rpm, the 420 Cobra Jet had 370 horsepower at 5,400 rpm and the Super Cobra Jet had 375 horsepower at 5,600 rpm. The bore measurement was 4.36 inches, and the stroke was 3.69 inches.
  
  

Dwell Angle

• The majority of Ford 429 engines produced used a dwell angle between 27 and 29 degrees. The standard 429 Thunder Jet had this dwell angle specification throughout its production from 1968. The 429 Cobra Jet and Super Cobra Jet engines used this dwell angle until 1971. After 1971, the Cobra Jet engine had a dwell angle specification of 25 degrees, and the Super Cobra Jet had a dwell angle specification of 28 degrees.
  
  

Fuel System

• All three of the 429 engines had fuel systems with a four-barreled carburetor. The Cobra Jet had a Rochester carburetor, and the Super Cobra Jet had a Holley carburetor providing 780 cubic feet/minute. The cylinder head intake measurement of the standard 429 Thunder Jet was 2.08 inches, and the exhaust measurement was 1.66 inches. The cylinder head intake measurement of the Cobra Jet was 2.25 inches, and the exhaust measurement was 1.72 inches.
  
  

Gap and Timing Measurements

• Initially, the spark plug gap measured 0.035 inches, and the point gap measured 0.021 to 0.017 inches for all three 429 engines. After 1971, the spark plug gap on all three models was reduced to 0.034 inches, while the point gap on the Cobra Jet and Super Cobra Jet was reduced to 0.020 inches. The timing measured 6-degrees before top dead center (BTDC) in the standard 429 Thunder Jet, and 10-degrees BTDC in the 429 Cobra Jet and Super Cobra Jet. In 1971, the 429 Thunder Jet changed to a 4-degree BTDC timing.