Thread: Oldsmobile heads

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i have an oldsmobile 403 and im putting 350 heads on it to rasie the compression to 9.5:1. I will be using headers and alumium intake with a factory 800 cfm carb. the intake valves on the 350 heads are 1.875 inches. I've read that smaller valves increase your low end torque. but in this case are they too small causing lost of power. im going be using this car as a daily driver. and would like to use it to blow the little rice rockets of the line. Somebody told me that i needed larger valves for a 403 then what i have so i just dont know.


Any answers are greatly apreciated.

Mark

The 1.85 valves are enough for this engine. As the 403 is a low-Rpm engine anyway. The intake runners for the 350 and 403 are the same on the factory intakes(or close enough) that it shouldnt be an issue. Unless you plan to have very low gearing, or race it full bore past 6000Rpms, dont worry yourself. However, compression is an issue with the 403, and so is cooling. Keep a thin head gasket, and be sure to triple-core that radiator. Hope this helps.