Best Aluminum Heads for an SBC 350 — AFR vs Dart vs Trick Flow vs Edelbrock vs Brodix
TL;DR: On a 350, the head that wins is almost never the one with the biggest runner. A 4.000" bore shrouds a large intake valve, and a 3.480" stroke caps the rpm where a big port ever gets to work — so a 170–195 cc intake runner with a 62–65 cc chamber is the honest answer for most street 350s, and 200–220 cc only starts paying on a 383 or an engine that genuinely lives past 6,000 rpm. Before you compare CFM, clear four fitment gates: intake bolt pattern (standard vs Vortec), spark plug angle, valve size against your bore, and the compression ratio the chamber hands you. Get those right and any of the five brands below will make good power; get them wrong and the best casting in the catalog will run worse than the iron heads you took off.
If you are cross-shopping AFR Eliminator against Dart Pro 1 against Trick Flow Super 23 and cannot work out why three heads with similar runner numbers get recommended for very different builds, this guide puts the decision in the order it actually has to be made.
Why aluminum, and what it actually buys you
Aluminum is not automatically more power. It buys four specific things, and it costs you two.
Weight. A pair of aluminum 23° heads saves a substantial amount of weight over a pair of iron castings (the exact delta varies by casting; weigh yours if corner weight matters). On a street car that is the single biggest weight reduction available for the money, and it comes off the front axle where it helps handling most.
Detonation margin. Aluminum pulls heat out of the chamber faster than iron. The practical result is roughly half a point to a full point more compression on the same pump gas than an equivalent iron head would tolerate. That is not a marketing number — it is the reason a 10.5:1 aluminum-headed 350 lives happily on 91 octane while a 10.5:1 iron-headed one rattles.
Repairability. Cracked or eroded aluminum welds. A cracked iron head is usually scrap. On a 30-year-old engine family this matters more than people expect.
A modern port, as a package deal. The real airflow advantage is not the metal — it is that aftermarket aluminum castings were designed decades after the factory iron ones. You are buying a better port shape, a better chamber, screw-in studs, guide plates, and hardened seats, all of which happen to arrive in aluminum.
The costs: aluminum moves more with heat, so fastener choice and gasket choice stop being optional, and every aluminum head is softer at the deck than iron, so an over-torqued or repeatedly re-used bolt pulls threads that iron would have shrugged off. Budget head studs and a proper head gasket into the head decision, not after it.
The four gates to clear before you shop by CFM
Every 350 head in our small-block Chevy 350 hub is filtered against these. Work them in this order.
1. Standard bolt pattern vs Vortec pattern. This is the single most common ordering mistake in the category. The 1996–2002 Vortec L31 head uses a different intake manifold bolt pattern and angle than every earlier small block, plus center-bolt valve covers. Aftermarket heads are sold in both configurations — Edelbrock, for instance, catalogs a Performer RPM in a standard pattern and a separate Vortec-pattern casting. Match the head to the intake you own, or budget a new intake manifold into the build. A "Vortec" head and a standard Performer intake do not bolt together, and no gasket fixes it.
2. Straight plug vs angle plug — check your headers first. Angle-plug heads move the spark plug toward the exhaust valve, which unshrouds the chamber slightly and is worth real power at high lift. They also move the plug into a place where some long-tube headers, and most factory manifolds, no longer clear. If you are not changing headers, buy straight plug.
3. Valve size against your bore. A 350 is 4.000". A 2.02" intake valve sitting that close to the cylinder wall is shrouded — the head flows on the bench and does not flow in the engine, because the wall stands in the way of the curtain area. This is why a 195 cc head with a 2.02" valve frequently beats a 220 cc head with the same valve on a stock-bore 350, and why the same 220 cc head wakes up on a 383 with a 4.030" bore. If you are staying at 4.000", 1.94"–2.00" intake valves are the safer choice unless the block is being bored and the bores notched.
4. Chamber cc — do the compression math before you fall in love. Swapping a 76 cc iron chamber for a 64 cc aluminum one on the same short block adds roughly a full point of compression. That is usually good. Going to a 62 cc chamber on a flat-top piston with a tight deck can put a stock-rebuild 350 near 10.8:1, which is more than a cast piston and a mild cam want on pump gas. Pick the chamber to land the compression you want, then argue about runner volume.
| Chamber (cc) | Flat-top, zero-deck, 0.041" gasket | Dished piston (−6 cc) | Practical read |
|---|---|---|---|
| 58 | ~11.0 : 1 | ~10.3 : 1 | Race gas or a very tight quench and a big cam |
| 62 | ~10.6 : 1 | ~9.9 : 1 | Aggressive pump-gas street; needs tune discipline |
| 64 | ~10.4 : 1 | ~9.7 : 1 | The default answer for a street 350 |
| 67–70 | ~10.0 : 1 | ~9.4 : 1 | Boost, nitrous, iron-block towing, low-octane regions |
Figures are estimates for a 350 at 4.000" × 3.480" with a nominal valve relief. Compute your own with your measured deck height, gasket compressed thickness and piston volume — a small deck-height error moves the answer more than a small chamber difference.
Runner volume: match it to rpm, not to ambition
Intake runner volume sets port velocity. Too small and the head chokes at the top; too big and the port goes lazy down low, and a street 350 lives down low. Displacement and rpm together set the demand.
| Intake runner | Best fit | Realistic rpm band | Typical build |
|---|---|---|---|
| 165–180 cc | Stock-stroke 350, mild hydraulic cam | 1,500–5,500 | Truck, tow, cruiser, stock converter and gears |
| 185–200 cc | 350 with a real street cam, or a mild 383 | 2,000–6,000 | The mainstream street/strip answer |
| 200–215 cc | 383 stroker, or a 350 with headwork, gears and converter | 2,500–6,500 | Street/strip, 3.73+ gear, 2,800 rpm stall |
| 215–235 cc | 383–406, race valvetrain, big solid roller | 3,500–7,000+ | Bracket and race only; miserable on the street |
Two rules that save people money:
- A 350 that shifts at 5,800 rpm cannot use a 220 cc runner. You will give away part-throttle response and low-lift flow to buy peak flow you never reach.
- Low-lift flow matters more than peak flow on a street engine. Your cam spends most of its time between 0.100" and 0.400" lift. A head that flows well at 0.200" makes a car feel fast; a head that only wins the 0.600" column makes a dyno sheet look good.
The five-brand comparison
Every casting family below exists in our cylinder head collection for the 350/383 Gen I small block. Flow figures are deliberately omitted — manufacturers test on different benches at different depressions and the numbers are not comparable across brands. Compare runner volume, chamber, valve size and assembled spring rating instead, which are apples to apples.
| Brand / family | Runner sizes carried | Chamber | Reputation in one line | Best fit |
|---|---|---|---|---|
| AFR Eliminator | 180, 195, 210, 220, 235 cc | 64–65 cc | The CNC-ported chamber benchmark; strongest low- and mid-lift flow per cc of runner in the class | The pick when you want the smallest runner that will make your target power |
| Dart Pro 1 | 200, 215, 230 cc | 64 cc | Thick decks, generous material for future porting, race-durable casting | Nitrous, boost, high cylinder pressure, or a head you plan to port later |
| Trick Flow Super 23 | 195, 215 cc | 64 cc | Excellent out-of-the-box street package; strong value in assembled form | Street/strip 350 and 383 builds that will never be ported |
| Edelbrock (E-Street 170, Performer RPM 200, Performer RPM Vortec, Victor Jr 210) | 170–210 cc | 64–70 cc | The widest fitment spread, including the only mainstream Vortec-pattern aluminum option here | Bolt-on replacements and mild builds where intake compatibility is the constraint |
| Brodix (IK-180, IK-200, Track 1 210) | 180, 200, 210 cc | 64–67 cc | Lightweight castings with a long circle-track pedigree | Weight-sensitive builds and sustained-rpm use |
How to read that table. AFR's advantage is chamber and port efficiency — you generally use a smaller AFR runner than you would from another brand to hit the same power, which is exactly what a street 350 wants. Dart's advantage is metal: more of it, in the deck and around the ports, which is what a boosted or sprayed engine wants and what a porter wants. Trick Flow's advantage is that the assembled package is genuinely finished — the spring and retainer combination it ships with suits the cams most people actually buy. Edelbrock's advantage is fitment coverage, including the Vortec-pattern casting that solves gate #1 without a new intake. Brodix's advantage is weight and durability under sustained rpm.
None of these is "the best head." They are five different answers to five different constraints.
Bare or assembled? The spring is the real decision
Assembled heads arrive with valves, springs, retainers and seals installed. That is convenient and usually cheaper than buying the parts separately — but every assembled head ships with a spring rated to a maximum valve lift, typically enough for a mild street cam and no more (the rating is per casting and per brand — confirm against the specific SKU).
The decision is simple:
- Your cam is inside the spring's lift rating and uses a hydraulic flat tappet or mild hydraulic roller → buy assembled. Bolt them on.
- Your cam exceeds that lift, uses a solid roller, or you have not chosen the cam yet → buy bare and spec the valve springs to the cam. Installing a big roller cam under stock-rated assembled springs is how people coil-bind a fresh set of heads on the first start.
Buy the camshaft and the heads as one decision, in that order. The cam sets the spring, the spring sets bare-vs-assembled, and the head's runner volume should be chosen for the same rpm band the cam is ground for.
What else has to change when the heads do
Plan for all of it up front. This list is where head swaps go over budget:
- Pushrod length must be re-checked. Aftermarket heads change valve tip height and deck thickness. Measure with an adjustable checking pushrod; do not assume stock length.
- Intake manifold — mandatory if you crossed the standard/Vortec pattern line, and worth matching to runner volume regardless.
- Head bolts or studs. Aluminum needs correct washers and correct torque. Studs are the better answer any time the heads will come off again.
- Head gasket bore and thickness set your quench. A 0.015" too-thick gasket gives away the detonation margin the aluminum just bought you.
- Accessory clearance. Angle-plug heads, tall valve covers and some aftermarket castings interfere with factory brackets, A/C and stock manifolds.
- Thermostat and coolant routing. Some castings relocate or delete the coolant crossover; check before the engine is in the car.
- Retorque. Aluminum relaxes after the first few heat cycles. Follow the fastener manufacturer's retorque guidance, and do it before you set final valve lash on a solid cam.
Browse the full SBC Gen I parts hub for the matching valvetrain, pistons and gasket sets when you spec the package.
FAQ
Will aluminum heads add horsepower on a stock 350? Yes, but the gain comes from the port and the compression increase, not the metal. A stock two-barrel 350 with a stock cam and stock intake will see a modest gain from a 170–180 cc aluminum head. The same heads on the same engine with a matched cam and intake will show far more, because the head is no longer the only restriction. Change one thing and you measure one thing.
Do I need to change my cam when I install aluminum heads? Not strictly — the heads will bolt on and run. But a head swap moves the engine's airflow ceiling upward, and a stock cam will not reach it. If the budget allows only one, most 350s gain more from a properly matched cam than from heads alone. Doing both together, matched to the same rpm band, is where the real gain is.
Are 64 cc chambers always the right choice for a 350? For a flat-top piston on pump gas, 64 cc is the mainstream answer. Choose larger (67–70 cc) if you run boost, nitrous, a lot of ignition timing, a heavy tow load, or low-octane fuel. Choose smaller (58–62 cc) only with dished pistons, race fuel, or a deliberately tight quench and a big-duration cam that bleeds cylinder pressure.
Can I run 2.02" intake valves on a stock 4.000" bore? You can, and many heads ship that way, but the valve is shrouded by the cylinder wall and you do not get all the flow you paid for. Notching or relieving the bore top helps. If the block is coming apart anyway and going 0.030" over, the shrouding problem eases considerably.
What is the difference between Vortec-pattern and standard heads? The intake manifold bolt pattern and angle, and the valve cover bolt arrangement. Vortec L31 heads use an 8-bolt intake pattern and center-bolt covers; earlier small blocks use a 12-bolt pattern and perimeter covers. They are not interchangeable without changing the intake manifold to match.
Do aluminum heads need a special head gasket? Not special, but chosen deliberately. Aluminum expands more than iron, so the gasket sees more relative motion at the fire ring. MLS gaskets handle that well and want a flat, well-finished deck surface; composite gaskets are more forgiving of a marginal surface. Match the gasket bore to your bore, and pick the compressed thickness that gives you the quench you want.
Should I buy bare heads and have them ported? Only if you are chasing a specific target that an off-the-shelf casting does not reach, and only with a porter whose work you can see flow numbers for. Modern CNC-ported castings from these five brands leave much less on the table than they did twenty years ago. Buying a thicker casting like a Dart specifically so it can be ported later is a legitimate plan; buying a cheap casting and hoping porting rescues it is not.
How much power will aluminum heads support on a 350? Runner volume and valve size set the ceiling long before the metal does. As a rough map: 170–180 cc supports a mild street build, 195–200 cc supports the mainstream 400–450 hp street 350, 210–220 cc supports a strong 383, and beyond that you are into builds where displacement, cam and rpm — not the head — are the limiting factors. Those power figures are planning brackets, not guarantees; they depend on cam, compression, induction and exhaust.
Core Powertrain Parts Tech Team. Specifications and part numbers referenced here should be confirmed against the manufacturer's current catalog before ordering.