Pontiac 4150 Northwind Intake w/ Water Crossover - CNC Port Matched to Butler Wide Port Heads (w/ Plenum Work) BPI-NW-4150-WP

About the Butler Northwind 4150 (with water crossover) intake: Low Rise 356-T6 Aircraft Aluminum 5 Axis CNC machined 4150 Flange Standard North Wind Intake with as cast port Can be port matched to our BPI Ported Heads Pontiac 4150 Northwind Intake w/ Water Crossover **1 1/4" Shorter Than Victor Intake**

Wide-port manifold, matched to the big heads. Machined and port matched to Butler Wide Port, Victor Pro Port, and Kauffman heads. The wide-port opening is relocated and enlarged, so it requires this wide-port manifold and the matching wide-port intake gasket (SPM-5420PS family) — giving the largest-flowing Pontiac heads a manifold that actually lines up with them.

The Butler CNC port-matching process. A port match is only worth doing if it's done right. Out of the box, an intake manifold and a cylinder head are cast separately and never machined to meet each other — leaving a step, offset, or size mismatch at the port opening that trips the incoming air and fuel right at the doorway to the cylinder, exactly where you least want turbulence. For years the only fix was a gasket scribe and a die grinder by hand: slow, inconsistent side to side, impossible to repeat, and easy to over-grind into a reversion step that actually costs you flow. Butler invested in a better way. Every Butler port match is modeled in 3D from the actual head port, programmed into repeatable toolpaths, and cut on our 5-axis Haas UMC machining center using dedicated fixturing that locates every manifold exactly the same way. Each opening is machined to the correct size and shape, then blended smoothly back into the manifold's own casting so the transition is gradual rather than a cliff — identical on all eight ports, cylinder to cylinder.

Why it matters. A machined match is precise, symmetrical, and repeatable, and it's matched to the real port it bolts to — not a generic gasket outline. You get the airflow benefit of a perfect port match without the risk of a hand-grinding mistake that can't be undone. Modeled, machined, matched, and finished in-house by Butler Performance — the Pontiac experts.