You need to get a Casting # book and look up which heads you have.
The intake valves are bigger, and lead to the carburetor. the exhaust valves are smaller and lead to the manifolds or headers.
The exhast valves are larger.
The exhaust valves are smaller and lead to the exhaust manifold.
exhaust
In a 1998 Chevy Malibu with a 3.1-liter engine, the intake valves are generally larger than the exhaust valves. The intake valves are located on the side of the engine that faces the air intake system, while the exhaust valves are positioned on the side connected to the exhaust manifold. Additionally, the intake valves typically have a longer stem compared to the exhaust valves, which can help in distinguishing between them. Always refer to the vehicle's service manual for precise specifications and diagrams.
In the cylinder heads.
The intakes are always bigger than the exhausts.
1973 350 Corvette. 76cc chambers. 2.02`` intake valves 1.6`` exhaust valves.
That's an easy one. Take the rocker box's, (valve covers) off. The valves that line up with the intake runners, are intakes, and the ones that line up with the exhaust, are exhaust. If the heads are off, always the larger valve, is intake.
From the front of the head it's EIIEEIIE. This is the same on both sides - (I=Intake, E=Exhaust) With the valve covers off the rocker that aligns with the exhaust port is the exhaust the other will align with the intake manifold runner this would be your intake
Front to rear, either side, E,I,I,E,E,I,I,E.
305s had 1.72" intakes with 1.50" exhaust valves. Depending on the 350, it could be the same, or have either 1.94" intake and 1.50" exhaust, or 2.02" intake with 1.60" exhaust.