Hey Here WE ARE with YET One MORE Classic GM Engine__the OLDS 403
Oldsmobile released the small-block 403 in 1976 for the 1977 model year. General Motors designed the 403 to replace the big-block Olds 455, which GM decided had outlived its usefulness.
The Olds 403 was designed to be a big block in a small-block package. As a result, it has a bore of 4.351 inches (110.5 mm), giving it one of the widest bores of any factory small-block V8. Oldsmobile discontinued the 403 after the 1979 model year. General Motors used the Olds 403 as a ‘corporate engine’ across its line of brands. Oldsmobile, Pontiac, Buick, and GMC offered the Olds 403 in passenger cars and RVs.
Engine builders know that it’s often easier to generate high RPM power with a short stroke. This is where the Olds 403 shines. In addition to its wide bore, it also has an unusually short 3.385-inch stroke.
These characteristics make the Olds 403 an excellent choice (on paper) for high performance builds, as it has the ‘perfect combination’ of bore and stroke.
Olds 403 Specifications
The Olds 403 was found in a variety of General Motors vehicles from model year 1977 to 1979. The famous 1977–1978 GMC Motorhome also came equipped with an Oldsmobile 403. A 1977 Oldsmobile Delta 88 served as the official Indy 500 pace car, marking the fourth consecutive year that Oldsmobile held the title.
ENGINE OLDSMOBILE 403
MANUFACTURER GENERAL MOTORS
YEARS PRODUCED 1977, 1978, 1979
DISPLACEMENT 403CI (6.6L)
CONFIGURATION SMALL BLOCK V8
COMPRESSION RATIO 8.0:1
BORE 4.351 INCHES (110.5 MM)
STROKE 3.385 INCHES (86.0 MM)
HORSEPOWER 185 HP (138 kW)
TORQUE 320 LB-FT (430 N-m)
Oldsmobile vehicles equipped with the 403 CID:
1977 Cutlass
1977 442
1977 Vista Cruiser
1977–1978 Delta 88
1977–1978 Toronado
1977–1979 98
1977–1979 Custom Cruiser
77 delta 88 olds 403
Buick vehicles equipped with the 403 CID:
1977 Century Estate
1977–1978 Riviera
1977–1979 Electra
1977–1979 Estate Wagon
1977–1979 LeSabre
Pontiac vehicles equipped with the 403 CID:
1977 Bonneville
1977 Grand Prix (California Emissions Package)
1977-1979 Catalina Safari
1977–1979 Trans Am
1977–1979 Firebird Formula 6.6L