Rams Horn and Smog Exhaust Manifolds

On the 400 cid SBC, I had to ditch the original exhaust manifolds for two reasons: first they were smog busters and had the air injectors in them and second the passenger side manifold exited into the firewall. I needed the passenger side exhaust to exit between cylinders 4 and 6 in the middle of the block and straight down. Here's a website that lists pretty much every SBC exhaust manifold with pictures to help find the right one.

Smog buster exhaust

Smog buster exhaust with air injectors running across the top

I replaced the passenger-side exhaust manifold with a driver-side ram's horn manifold which probably came out of late 60s to early 70s Chev pick-up. The driver-side ram's horn manifold has mounting bolts for the power steering pump. They're called ram's horn because they look like ram's horns and supposedly flow very well. This one was painted silver which should dull pretty quick once the engine runs. I will probably grind off the power steering pump mounting bolt flange just for looks. There are two sizes of ram's horn manifolds: 2" and 2 1/2". Corvette's and high performance cars used the larger size for better flow, consequently they are about 5-8 times more expensive than the 2" outlet. I paid $30 for the 2" pair and the local Corvette restoration place wanted $200 for one 2 1/2" manifolds in bad shape.

Silver painted ram's horn

Shiny painted ram's horn exhaust manifold for passenger-side.

Poor casting

Poor casting - lower right corner flash restricts exhaust

It's difficult to see but the lower right corner is not rounded but has flashing present from poor factory casting. I will be grinding off the excess flashing.

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Copyright July 2011 Eugene Blanchard