Product Summary

283, 302, 307, 327, 350, 383, Bare Cylinder Head Style

  • Features 180cc intake runner, 62cc exhaust runner, 2.02" intake/1.60" exhaust valves, 1.560" max spring pocket diameter
  • Cast from premium quality aluminum that shaves 40 lbs. off the nose of your car vs. heavy iron heads
  • No accessory bolt holes, just like the original heads
  • Improved port/chamber shape for better performance with the 3-angle machined valve job that promotes better flow, especially at low-to-mid lifts
  • Designed for 4" bore 1962-86 small block engines (302/327/350)

Key Specs

Cylinder Head StyleBare
Material TypeAluminum
Combustion Chamber Volume64cc
Intake Runner Volume180cc

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Step back in time with our modern reproduction of the iconic Chevy 461 double hump cylinder heads, now cast in lightweight aluminum! Also known as "fuelie" heads, the 3782461 castings were used on many legendary Chevrolets from 1961-1967. Our all-new cylinder head casting is a modern take with all the old-school looks you desire out of a reproduction camel hump head. Features like fast-burn combustion chambers, high-velocity ports, large diameter valve springs, and positive stop valve seals bring the vaunted camel hump heads into the 21st Century.

Save yourself the hassles of hunting down original GM 3782461, 3782461X or 3890462 castings, only to find out they can't be saved. By now, most original 461 heads have had multiple valve jobs and milled decks, which means buying a set is a gamble. Plus, when considering all the costs involved in machining them to accept modern valvetrain components, our all-new castings are a very cost-effective alternative.

GM produced many versions of the Chevy camel back heads, however these are visual copies of the very first double hump heads, often referred to as "fuelies" because of their use on Rochester Ram-Jet equipped Corvettes. As such, these heads will perfectly complement your nostalgic hot rod build or restomod muscle car, all the way down to the textured as-cast finish and cast parting line across the exhaust port side, just like the original heads. Plus, the raised valve cover rail means that full roller rocker arms will fit underneath original Corvette valve covers ('59-up covers). With a coat of Chevy Orange paint, you'll have everyone convinced you're running an original set of 461 double hump heads.

Take note that these heads have no accessory bolt holes for the front drive (just like original 461s). There are a couple options to mount your alternator/generator: 1) you can rely on accessory mounts off the block or water pump, or 2) pair these heads with our "rams horn" exhaust manifolds 9300328. These 2-1/2" outlet manifolds feature built-in mounts for your generator/alternator and are correct for '62-'63 Corvettes. To utilize this method, you will also need both 91603050 and 91067850 to mount the generator/alternator. When going this route, you may also be able to use a lower power steering pump bracket such as 91332902 or 91033727, depending on your pump and frame/steering box clearance. 

The original 3782461 castings delivered well over 1.1 hp/ci on many legendary Chevy models throughout the early ‘60s, which was a significant engineering achievement for the time. Highlights include the '61 Corvette 283/315hp and '62 Corvette 327/360hp (both with Rochester fuel injection and "Duntov" camshaft), the '63 Chevy 327/340hp, the '64 Chevy 327/365hp L76 and 327/375hp L84 (both with the "30-30" camshaft), and the'65 Chevy 327/350hp L79. With the undercover features included in these bare heads, you can expect even more performance out of your 283/302/327/350/383 SBC. If you're pairing these heads with a flat tappet camshaft under .550" lift, consider our assembled heads 9103782462.


  • Visually similar to GM casting # 3782461 which first appeared on the 1961 Corvette “fuelie”
  • No accessory bolt holes, just like the original heads
  • Heads are sold EACH
  • Aluminum heads shave 40 lbs. off the nose of your car vs. iron heads
  • Improved port/chamber shape for better performance and efficiency
  • Standard port location for use with most intake and exhaust manifolds
  • 180cc intake port volume (factory 461 casting was 160cc)
  • 62cc exhaust port volume (same as factory 461)
  • 64cc fast-burn combustion chambers deliver big power gains vs. 461 castings
  • 2.02” intake/1.60” exhaust valves (most 461 castings were 1.94/1.50)
  • 3-angle valve job promotes better flow, especially at low-to-mid lifts
  • Intake flows 232 CFM @ .500” lift
  • Exhaust flows 173 CFM @ .500” lift
  • Accepts both perimeter and center bolt valve covers
  • 1.560” max spring pocket diameter gives you many valve spring options
  • High nickel powdered metal valve seats provide optimum heat transfer and wear characteristics
  • Manganese bronze valve guides reduce friction
  • Valve guides are compatible with all common valve materials and fuels
  • Accepts modern positive stop valve stem seals for better oil control
  • Machined for 3/8” screw-in rocker arm studs and guide plates (not included)
  • Blocked exhaust heat riser manifold crossover port
  • 3/8” NPT coolant temperature probe port
  • Designed for 1962-86 small block engines (302/327/350)
  • Consider assembled heads 9103782462 for cams under .550" lift


They'll fit on a bored out 283 block (2.02/1.60 valves)

o Images show a 3.910 bore fixture (0.035 over 283) sitting on top of the head

o The valves cleared the bore wall 

(last 2 images show valves open)

o The combustion chamber measures exactly 4 at the widest point, so there is a slight overhang

o This was done with no offset dowel pins 

(no funny business)

Intake valve throat is 89%

Exhaust valve throat is 85%

Flow numbers that are posted were measured with a SAENZ 600 bench, 4.030 bore fixture, 1205-style intake fixture, and 28 of water

Exhaust port gained 20 CFM above advertised number by adding a 1-5/8 pipe (header), and a larger 1-7/8 pipe flowed the exact same

Combustion chamber volume number was calculated using an Autolite 3934 spark plug 

CARB Warning

For race/ off road use or for use on pre-1966 vehicles.

Emissions warning: this part only legal for sale or use in California for racing (competition) vehicles which may never be used, registered, or licensed for use upon a public highway, or if installed in vehicles model-year 1965 or older; motorcycles model-year 1977 or older; or off-highway recreational vehicles (such as off-road motorcycles and all-terrain vehicles) model-year 1996 and older. Any other use renders the vehicle tampered and not legal for use on California public highways (any public street or roadway, public dirt road, public park, or publicly maintained right of way open to the use of the public for vehicular travel). Violations subject to $37,500 penalty per violation per vehicle, revocation of registration, loss of use on California public right of ways, and proof of correction for tampering. There are similar restrictions and penalties under federal law and the laws of all other states with penalties under federal law of up to approximately $45,268 per tampered vehicle and/or engine.


MFG. Part #
BrandSpeedway Motors
Cylinder Head StyleBare
Material TypeAluminum
Combustion Chamber Volume64cc
Intake Runner Volume180cc
Exhaust Runner Volume62cc
Combustion Chamber Volume Range60cc - 69cc
Intake Runner Volume Range180cc - 189cc
Exhaust Runner Volume Range60cc - 69cc
Combustion Chamber StyleHeart
CNC-Machined RunnersNo
CNC-Machined Combustion ChamberNo
Spark Plug StyleStraight
Intake Port ShapeRectangle
Intake Port LocationStandard
Exhaust Port ShapeSquare
Exhaust Port LocationStandard
Intake Valve Diameter2.02"
Intake Valves IncludedNo
Intake Valve Angle23 °
Exhaust Valve Diameter1.6"
Exhaust Valves IncludedNo
Exhaust Valve Angle23 °
Machined for O-RingNo
Valve Seat Machine Style3-angle
Valve Seats MachinedYes
Valve Seat MaterialPowdered Metal
Valve Stem Seals IncludedNo
Valve Stem Seal TypePositive Stop
Valve Guides IncludedYes
Valve Guide MaterialManganese Bronze
Retainers IncludedNo
Guideplate Pushrod Size0.312"
Rocker Arms IncludedNo
Rocker Arm Studs IncludedNo
Stud Diameter1.375"
Rocker Arm Nuts IncludedNo
Oiling StyleThrough Pushrod
Heat CrossoverNo
Steam Holes DrilledNo
Accessory Bolt Holes DrilledNo
Valve Cover Mounting StyleCenter and Perimeter Bolt
NotesBare head weighs 19.6 lbs. each.
Sold in QuantityEach