It's long been known that the key to making power is having a good cylinder head.
Although all of GM's divisions produced big-block-powered musclecars back in the day, most of which have gone on to become legendary, serious performance efforts have often been forced to rely on the best factory iron castings after grinding, cutting, welding, and otherwise manipulating them into submission.
The good news is that in the last few years, a crop of new cylinder heads and intake manifolds have been introduced through the aftermarket, and from a wide variety of sources. This hardware has made the 500hp benchmark a whole lot easier to reach, while also opening the door to serious levels of power previously reserved for "mainstream" racers. We've complied some of the latest "B-O-P-C" cylinder head offerings along with suggestions for intake manifolds to complement them. Rats and Hemis beware.
BUICK
TA Performance
For nearly two decades, TA Performance has been providing Buick enthusiasts with the hardware they seek in the never-ending quest for increased performance. TA goes beyond simple bolt-ons and offers its own aluminum intake manifolds and cylinder heads to turn up the wick for 400/430/455 engines. In fact, TA now offers six different head castings for the Buick V-8, starting with the Stage I Street Eliminator and continuing to Stage IV raised-port castings. Although the Stage I Street Eliminator appears to be an entry-level piece, it's capable of around 285 cfm on the intake side--good enough to easily support a 500hp street/strip engine. Check TA's Web site for other versions. TA also offers its own intake manifolds, including the SP1 street/strip single-plane and the SPX race-type dual-plane. For mild street engines, TA points out that Edelbrock is about to re-release its B4B Buick dual-plane manifold as well.
Stage I Street Eliminator
Application: '67-'76 Buick big-block V-8
Casting material: 356-T6
Combustion chamber volume: 64 cc
Intake port volume: Not available
Valve type: Stainless high-flow swirl polish
Valve sizes: 2.130/1.755-inch (Stage I spec)
Valvespring diameter: 1.385-inch (1.500-inch available)
Rocker mounting: Stock rocker shaft
Valve guides: Manganese bronze
Valve seats: Hardened steel
Other features/requirements: Accepts stock intake and exhaust and stock valvetrain plus all stock accessory brackets. Can be made to look nearly stock if desired.
Bulldog Performance
Although Bulldog is a relative new player in the aluminum performance engine component business, open since 2002, proprietor Dick Bradshaw has been a pattern-maker for many years, with extensive experience in the design of V-8 cylinder heads as well as intake manifolds. Assisting heavily with these efforts was Pro Stock head-porting guru Mike Duke of Mike Duke Racing. Bulldog's goal is to provide cylinder heads (and intake manifolds) that offer substantial gains in performance while remaining compatible with stock-type intake and exhaust hardware. Applications started with Cadillac V-8s and have rapidly broadened to include many other "orphan" engines.
Bulldog Buick
Application: '67-'76 Buick big-block V-8 (400, 430, 455)
Casting material: 356-T6
Combustion chamber volume: 66 cc
Intake port volume: 250 cc
Valve type: Stainless one-piece
Valve sizes: 2.19/1.81-inch
Valvespring diameter: 1.550-inch
Rocker mounting: Stock rocker shaft pedestals
Valve guides: Bronze
Valve seats: Powdered metal
Other features/requirements: Accepts stock intake, exhaust, and valvetrain, plus all stock accessory brackets. Requires longer pushrods due to longer valves
OLDS
Edelbrock
With the exception of a couple of specialty parts makers, the Olds guys had been largely ignored by the aftermarket for years. Fortunately, Edelbrock stepped up with its Performer RPM Olds aluminum head a few years back, making big power numbers much easier to attain with Rocket engines. Like most Edelbrock Performer heads, the Olds version is very compatible with factory parts and is made using high-quality castings and parts with detailed finish work, right down to the Heli-Coiled rocker and exhaust bolt-holes. To back it up, Edelbrock recently introduced its Olds version of the Victor race-oriented single-plane intake in both standard square-flange and 4500-series flange.
Performer RPM Olds Aluminum Cylinder Heads
Application: '65-'76 Oldsmobile 400, 425, and 455ci V-8
Casting material: 356-T6
Combustion chamber volume: 77 cc
Intake port volume: 188 cc
Valve type: Stainless, one-piece, swirl-polished
Valve sizes: 2.072/1.680-inch
Valvespring diameter: 1.45-inch
Rocker mounting: 7⁄16-inch stud
Valve guides: Manganese-bronze
Valve seats: Hardened ductile iron
Other features/requirements: Accepts stock-type intake and exhaust manifolds and valve covers, requires aftermarket rocker arms (stock pedestal-mounts replaced with studs). Can be made to work with 350-403 Olds small-blocks with port matching per Edelbrock's instruction.
Bulldog Performance
Among the earliest of Bulldog's aluminum cylinder head efforts is the Oldsmobile variant. Proprietor Dick Bradshaw tells us that the lack of real estate within the confines of the stock Olds head made Bulldog's goals of retaining compatibility with stock parts while substantially improving performance a challenging proposition. Despite this, the Bulldog head does indeed outshine stock castings by a large margin, flowing 292 cfm at 0.700-inch lift, (279 cfm at 0.500 lift) on the intake side.
Bulldog Oldsmobile Aluminum Head
Application: '65-'76 Olds big- and small-block V-8
Casting material: 356-T6
Combustion chamber volume: 76 cc
Intake port volume: 240 cc (270 cc raised port)
Valve type: Stainless steel, one-piece
Valve sizes: 2.15/1.75-inch
Valvespring diameter: 1.550-inch
Rocker mounting: 7⁄16-inch stud w/guideplates
Valve guides: Bronze
Valve seats: Powdered metal
Spark-plug location: Angled
Other features/requirements: Accepts stock intake and exhaust manifolds (raised-port requires spacer, which is supplied), all stock accessory holds drilled and tapped. Can also be configured for small-block Olds.
Mondello Performance Products
The name Mondello has been closely associated with Olds V-8 performance since the days when W-machines were still factory fresh. Today, Joe Mondello is also known as a master cylinder head porter, even instructing others in the elusive art. Mondello was involved with the development of the Edelbrock aluminum head, and now Mondello Performance has teamed with Glenn Knowlton to produce an ultra high-performance Oldsmobile aluminum head. These heads can be configured for street engines or ported for serious drag racing and are sold with a port-matched Mondello Posiflow Air Gap intake manifold.
Mondello/Knowlton Oldsmobile Aluminum Head
Application: '65-'76 Oldsmobile big-block V-8
Casting material: 356-T6
Combustion chamber volume: 75 cc
Intake port volume: 375 cc
Valve type: Stainless, one-piece
Valve sizes: 2.250/1.680-inch
Valvespring diameter: 1.625-inch
Rocker mounting: 7⁄16-inch stud w/guideplates
Valve guides: Bronze
Other features: Offered in street or race trim. Race heads are fully ported and include a port-matched Mondello Posiflow intake and tall valve covers.
Rocket Racing & Performance
Dedicated to the pursuit of Oldsmobile performance, Rocket Racing offers a full line of performance parts and services aimed at increasing the performance of Olds-powered vehicles. The complete approach to Olds performance led Rocket Racing to team with Kayenel Machine to create a high-performance aluminum Olds head. Of course, it also led RRP to design the head to cover a broad range of applications, from street/strip to full-race. RRP also offers its own intake manifolds and valve covers along with other unique Olds performance parts.
RRP Oldsmobile Aluminum Head
Application: '66-'76 Oldsmobile V-8
Casting material: 356-T6
Combustion chamber volume: 75 cc CNC'd
Intake port volume: 190 cc as cast
Valve type: Stainless steel one-piece
Valve sizes: 2.150/1.625-inch
Valvespring diameter: 1.550-inch
Rocker mounting: 7⁄16-inch stud
Valve guides: Bronze
Valve seats: Powdered metal
Spark-plug location: Angled
Other features/requirements: Raised intake ports require use of Rocket Racing intake, and big-blocks must use intake flange adaptors (included); raised exhaust ports accept stock-type flange; accepts stock-type valve covers and accessory brackets; mechanical fuel pump causes no interference; symmetrical ports are clear of water passages to allow extensive porting.
PONTIAC
Edelbrock
The best factory performance parts have been getting increasingly scarce in the two-and-a-half decades since Pontiac V-8 production ceased. Thankfully, Edelbrock recognized the need and produced the Performer Pontiac aluminum head, patterned after the legendary Ram Air IV castings. Of course, while they were at it, the engineers at Edelbrock made some improvements. To support the improved airflow, Edelbrock offers a wide variety of Pontiac intake manifolds, including the Performer RPM dual-plane and Victor-series single-plane, now also available in an EFI version.
Performer RPM Aluminum Cylinder Heads
Application: Pontiac V-8 (326-455 ci), '55-'79
Casting material: 356-T6
Combustion chamber volume: 72 cc or 87 cc
Intake port volume: 215 cc
Valve type: Stainless steel, one-piece
Valve sizes: 2.11/1.66-inch
Valvespring diameter: 1.45-inch
Rocker mounting: 7⁄16-inch stud
Valve guides: Manganese-bronze
Valve seats: Hardened ductile iron
Other features/requirements: Requires use of Pontiac round-port-style headers/manifolds; accepts stock-type intake manifolds, valve covers, valvetrain, and accessory brackets.
DCI Motorsports
Although aluminum heads have been available for Pontiacs since the mid-'90s, DCI Motorsports felt there was a need for race-purposed aluminum castings, so it created them. Dubbed Tiger Heads, these aluminum castings are just reaching production as this is being written. Note that these are really intended for serious race Pontiacs, not mild street combinations. They will fit stock blocks, but require a 4.25-inch bore with the standard 1.75-inch exhaust valves. Smaller exhausts can be specified to fit smaller bores. Spacers are required to fit stock-type intakes, but they are provided. Initial reports claim the Tiger Heads are capable of flowing 400 cfm on the intake side--an impressive number for any type of engine.
Tiger Heads
Application: Pontiac V-8, '55-'79
Casting material: 356-T6
Combustion chamber volume: 75 cc (heart-shaped)
Intake port volume: 310 cc
Valve type: Stainless one-piece, 6.50-inch (stock RA IV is 5.20-inch) length
Valve sizes: 2.25/1.80-inch (2.35/1.90-inch optional)
Valve angles: 12 degrees (stock is 14) intake moved 0.070-inch from cylinder wall
Valvespring diameter: 1.620-inch
Rocker mounting: Custom rocker shaft
Valve guides: Bronze
Valve seats: Ductile iron
Spark-plug location: Angled (stock is straight)
Other features/requirements: Heads accept stock intake with provided spacer plates, exhaust is available in either D-port or round-port, though custom headers may be required, raised exhaust ports are an option.
Kauffman Racing Equipment
Kauffman Racing focuses on Pontiac high-performance engines and parts, but recently added aluminum cylinder heads to its lineup. These heads are a new design manufactured specifically for Kauffman Racing, and among the many features is the use of standard Pontiac D-port exhaust outlets.
KRE Pontiac Aluminum D-port
Application: '55-'79 Pontiac V-8 (350-455)
Casting material: 356-T6
Combustion chamber volume: 65 cc (race) or 85 cc (street)
Intake port volume: 185 cc
Valve type: Ferrea stainless one-piece
Valve sizes: 2.11/1.66-inch (larger available)
Valvespring diameter: Up to 1.65-inch
Rocker mounting: 7⁄16-inch stud
Valve guides: Bronze alloy
Valve seats: Hardened steel
Spark-plug location: Angled
Other features/requirements: Accepts stock-type intake, D-port exhaust, valve covers, and valvetrain, accepts all '65-'79 accessory brackets; can be used with 1.65:1 rockers with no additional clearancing. Requires special head bolts available from ARP.
Kayenel Machine
Back before there were Edelbrock heads for Pontiacs, there was the Wenzler aluminum head. Pontiac performance enthusiast Larry Wenzler spearheaded the project to create a high-performance head for Pontiacs as an alternative to seeking out rare and expensive Ram Air IV factory castings. The Wenzler head is based on an aluminum version of the iron RA IV. Of course, some improvements were made and extra material added, but early Wenzlers were really intended for the serious Pontiac racer. With the introduction of the Series II, the performance potential of the Wenzler head has been improved, plus they are now more user-friendly. As a higher-performance alternative for serious Pontiac racers, there is now the Wenzler Super Chief. These are raised-port castings with the potential to flow up to 430 cfm. The Super Chiefs require a shaft rocker system, Wenzler G-Ram intake (or fabricated intake), and custom headers.
Pontiac V-8
Casting material: 356-T6
Combustion chamber volume: 65 cc to 90 cc
Intake port volume: Not available
Valve type: SI stainless one-piece, swirl polished
Valve sizes: 2.11/1.77-inch (can accommodate 2.190/1.820-inch)
Valve angles: Stock, pushrods at 2-degree angle
Valvespring diameter: Up to 1.60-inch
Rocker mounting: 7⁄16-inch stud, relocated for pushrods
Valve guides: Bronze
Valve seats: High-chrome steel insert
Spark plugs: Angled, extended reach
Other features: Requires round-port exhaust, stock-type intake tough port matching required, mounts stock accessory brackets except A/C.
CADILLAC
Bulldog Performance
The first cylinder head developed by Bulldog was the Cadillac application, and according to Bulldog, that process revealed that the Cad has tremendous potential. The Bulldog heads go a long way toward releasing that potential, as the big-inch Cadillacs can now breathe deeply. Flow bench testing shows over 300 cfm on the intake side out-of-the-box, with plenty of room left for porting. The intake openings are CNC'd on the Cadillac heads, while the exhausts are not (we're told they needed no extra help). Bulldog also offers a single-plane intake for the Cadillac V-8 to support the heads, though stock-type intakes can be used. Edelbrock also offers a Performer dual-plane for the Cadillac V-8.
Bulldog Cadillac
Application: '68-'76 Cadillac V-8, 472-500 ci
Casting material: 356-T6
Combustion chamber volume: 76 cc
Intake port volume: 265 cc
Valve type: Stainless one-piece
Valve sizes: 2.19/1.84-inch
Valvespring diameter: 1.550-inch
Rocker mounting: Drilled and tapped for stock-type rockers, or studs and guideplates
Valve guides: Bronze
Valve seats: Powdered metal
Other features/requirements: Accepts stock intake, exhaust, and valvetrain, and all stock accessory brackets.
