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jdorour · 01-03-2006, 10:36 PM

The 403 CI engine is a low deck (small block) introduced in 1977 to replace the 455 as the top of the line Olds engine. The 403 does not have siemesed cylinders and has the same 3.385 inch stroke as the 260, 307, 330 and 350 engines.
The 403 was used in the entire Olds line as well as Buick, Motorhomes and The Pontiac TransAm.
It has "windowed" main webs that cause the bottom end to flex when under extreme loads but the engine is fine for street use. You can really wake a 403 up with a set of big block heads and a good cam.

01-03-2006, 10:36 PM	#3 (permalink)
jdorour Senior Member Join Date: Feb 2004 Location: Atlanta, GA. Posts: 123	The 403 CI engine is a low deck (small block) introduced in 1977 to replace the 455 as the top of the line Olds engine. The 403 does not have siemesed cylinders and has the same 3.385 inch stroke as the 260, 307, 330 and 350 engines. The 403 was used in the entire Olds line as well as Buick, Motorhomes and The Pontiac TransAm. It has "windowed" main webs that cause the bottom end to flex when under extreme loads but the engine is fine for street use. You can really wake a 403 up with a set of big block heads and a good cam. __________________ 1966 Ninety Eight Convertible - 425 Tri-Carb, Factory Dual Exh, Switch-Pitch THM400, 3.54 Posi. 1966 Catalina Wagon - 421 Tri-Power, M21, 4.11 Saf-T-Trac, 8 Bolt Wheels 1989 IROC-Z - 5.7TPI