PRI 2012: RHS Releases New 23-degree Manifolds, High-flow LS7 Head

RHS is now offering a new single-plane alloy intake manifold that matches directly with its 23-degree small-block Chevy head. The company is also releasing a new higher-flowing version of its Pro Elite LS7 CNC-ported rectangular port cylinder head to complement its LS Race block.

“These 23-degree manifolds will reduce the port-matching time for engine builders,” says Kevin Feeny of RHS. “They also have dual bolt patterns to work with all types of Gen I heads, including GM Vortec and late-model perimeter-corner mounting.”

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Other features on the manifold include 4150 carb flange, nitrous bosses, auxiliary water ports, integral water crossover and dual distributor mounts. RHS also offers an EFI version that comes with integral MAP and air-temperature sensors. Unique to the RHS EFI manifold are the injector-port bungs that angled to optimize injector spray to the intake valve. Both styles of intake manifolds can be ordered polished or as cast.

The new LS7 rectangular-port cylinder head now comes with 307cc intake runners. The previous Pro Elite model — which is still available — has 291cc intake runners.

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“You can build an LS7 up to 502 cubic inches with our race block,” says Feeny. “The larger engines demand larger runners in the cylinder head.”

The Pro Elite heads feature a raised (.220-inch) intake runner design that will fit stock and aftermarket LS7-style manifolds and valvetrain setups. They come with a 12-degree valve angle and utilize the 6-bolt design. Other features include .750-inch thick deck, .100-inch raised exhaust ports and reinforced rocker rails.

RHS’s LS block comes in standard 9.240- and 9.750-inch deck heights. It’s made from A357-T6 aluminum with Siamese-cast bore walls and press-inch spun-cast iron liners. The cam centerline is raised .388-inch and the block will accommodate a 60mm camshaft.

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