Butler Performance D-Port CNC Ported Aluminum Pontiac Cylinder Heads, (Pair)

Butler-built on genuine Edelbrock Performer RPM D-Port castings, CNC-ported in our shop to a 310–325+ CFM intake. Edelbrock Performer RPM heads make outstanding horsepower with strong low-speed torque and throttle response. Designed for 1965–79 Pontiac 389–455 V8s and built complete — ready to bolt on.

Assembled Complete — Ready to Bolt On

Each pair ships fully assembled with Ferrea stainless-steel valves (2.11" intake / 1.77" exhaust), performance valve springs matched to your application, chromoly locks, retainers and locators, Viton valve-stem seals, ARP rocker studs, and guide plates. Chambers are polished and pushrod holes are slotted for 1.65 rockers — both included in the price.

BP has done extensive flow-bench, dyno, and track testing with these heads — we have proven combinations for everything from 7-second race cars to 8- and 9-second street cars and daily drivers. Call for a head combo built to your target.

Choose Your Build

• Combustion Chamber: 65cc, 72cc (higher compression, performance/race), or 87cc (street-legal compression on 92 octane).
• Application: tell us the combo so we verify the right components.
• Cam Specs: supply your known specs so we confirm the spring package.
• Retainer: chromoly, titanium, or PAC-brand titanium with PAC locks.
• Valves: Ferrea 5000 (street performance) or 6000 (competition grade).
• Stealth: logo removal with optional custom-matched paint.
• Intake Gaskets: add the recommended SPM-5410-2 set.

Upgrades: roller valve springs, titanium retainers, and additional milling for compression. Already own Edelbrock D-Port heads? Send them to BPI to be ported and upgraded.

Fitment

For 1965–79 Pontiac 389–455 V8s (350 with 1.66" exhaust valves and a clearanced block). D-Port keeps the factory-style exhaust port for stock-style manifolds and standard D-port headers. Stock valve-cover and accessory-bolt locations retained. Recommended intake gasket: SPM-5410-2.

Not sure which chamber you need? Use our compression calculator to dial in your ratio by bore, stroke, gasket, and piston — or call and we'll spec it for you.

Why Edelbrock Castings?

Butler could run our own private-label castings — but cylinder-head metallurgy is unforgiving and foundry quality varies. So we build on the casting the industry trusts: Edelbrock. Every core is sand-cast, heat-treated, and finished in the USA, giving our machine shop a consistent, high-flowing starting point to blueprint to the Butler Standard.

• Casting, core production, pattern making, heat treating, engineering, and machining all done in-house in the USA
• More out-of-the-box flow than most aftermarket aluminum heads — before any porting (capable of ~325 CFM D-Port, ~340 CFM Round Port when CNC ported)
• Heli-Coil inserts in the rocker-stud and exhaust-bolt holes to protect the threads through torque and header R&R

The Butler Process

We don't pull a head out of a box and call it done. Every custom Butler head is built in our own shop: a precision valve job on Serdi seat-and-guide equipment (the same class of machine used in Formula One and top-tier racing), a valvetrain matched to your combination, and flow-bench verification. It bolts on ready to make the power you paid for.

Image may show a bare casting for reference. This item includes two (2) complete, assembled cylinder heads, custom built per order.