Bill Mitchell 061040 S/B Chevy Single Plane Intake Manifold. While most manufacturers of small block Chevy intake manifolds have designed their units around 350 c.i. engines, Bill Mitchell Products has developed a very efficient manifold for 383 c.i. & larger engines BMP intake manifolds on average show gains of 10+ HP over the competition.

In addition to out-powering the competition, it’s important to note that these single plane manifolds are designed to operate most efficiently in the 2500 to 7500 RPM range, and have the low-end throttle response and torque comparable to a dual plane. Look inside the plenum and you’ll see a “turtle” on the manifold floor that helps increase velocity for improved bottom-end performance.

• Plenum:  Single
• Flange:  4150
• Deck Height:  9.025″
• NOS Bosses:  Yes
• EFI Bosses:  No
• RPM Range:  2500-7500
• OAH:  5.625″
• Port Size:  2.000″ x 1.180″

Holley 4150 carb flange.