How do you tell the difference between a Chevy 400 and a Pontiac 400?

Answer 1

Many ways. Pontiac 400 has a cast aluminum timing cover, that mounts the water pump directly on it, Chevy 400 has a stamped steel timing cover, water pump mounts to the block. Pontic 400 has fuel pump on the drivers side, Chevy is on passenger side. Pontiac has a separate valley cover below the intake manifold, Chevy intake IS the valley cover. Pontiac distributor does not go through the intake manifold, Chevy does. Pontiac has 10 head bolts per side, Chevy has 17. Pontiac has long exhaust ports that bend 90 degrees from the side of the cylinder head, Chevy exhaust ports end at the face of the cylinder head. Pontiac spark plugs are above the exhaust manifolds, Chevy is below. Pontiac 400 is physically larger than the small block Chevy 400 also.