Chevy small-block engine head casting numbers identify the model year, horsepower range, valve and chamber size and the size of the intake and exhaust ports. The most common heads sought by engine builders are ones identified variously as the "Camel Back," "Double Hump" or "Humper" heads used on a range of passenger cars and performance vehicles.
The small-block engine was manufactured by General Motors for Chevrolet and other GM vehicles from to It featured the following cubic-inch displacements:, and The Chevyintroduced incan still be purchased today as a replacement engine.
More than 90 million small blocks have been produced. The casting number is a six- seven- or eight-digit number, depending on the model year and model of the vehicle, found stamped on the head. For example, the casting number belongs to cubic-inch V-8 engines on the to GMC pickup trucks. Casting number is found on ci engines on GM vehicles with a chamber size of 76cc and valve size of 2. The popular Camel Backs can still be found in wrecking yards specializing in American-made vehicles.
These heads are easily identified by the last three digits of the casting number:,and The Camel Backs are often confused with the "fuelie" heads found on fuel-injected Corvettes, but measurements of the intake and exhaust ports will reveal the Camel Backs are installed in the carburetedand engines.
Casting number identifies Camel Back heads on engines in to GM models. Number is found on heads on the to models equipped with the Number can be found on theand engines in to models.
Number is found in the and models with the and The models equipped with the is stamped with The casting numbers also can identify whether the is a factory-installed GM engine or a GM Goodwrench replacement engine.
882 Heads... Are they worth using?
Casting number identifies a replacement, or crate, engine for and later vehicles that can be equipped with the It also will have "Hecho en Mexico" Made in Mexico stamped on it. GM's Ontario, Canada, plant-manufactured engines for some of its older-model pickups and for the Studebaker Corp. Casting numbers and were used on the and Canadian-produced ci GM trucks, respectively. Number is stamped on Chevy engines, which were also used in the Studebaker Lark passenger cars. Number identified the used in the to Chevys, the Studebaker Avanti and the independent Avanti II after Studebaker ceased production in These heads are prone to crack.
This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information.
To submit your questions or ideas, or to simply learn more about It Still Runs, contact us. Camel Backs The popular Camel Backs can still be found in wrecking yards specializing in American-made vehicles. References MonteCarloSS.
About the Author This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information. Photo Credits under the hood image by Lucy Cherniak from Fotolia.Nov 3, 1. Messages: Likes Received: 0. Nov 3, 2. Messages: 1, Likes Received: 0. Both these heads aren't worth anything for performance,all the money you've put in them you could have bought a set of Vortecs that will flow better.
Nov 3, 3. Messages: 9, Likes Received: 2. The 's are the better of the 2 heads. Nov 3, 4. Depends on how much power your looking for. I had a set of 's on a: Z28 stock standard bore pretty tired comp cams H edelbrock rpm performer 2. Last edited: Nov 3, Nov 4, 5. Nov 4, 6. Messages: 4, Likes Received: 0. Last edited: Nov 4, Nov 4, 7. The 's have 70cc combustion chambers and 1. The 's have 76cc combustion chambers and 1. If the 's are already on the engine as you say I would just leave them.
With the extra compression they provide you will have more power over the 's even with the smaller valves. Or if you really want the heads make sure you use a thinner gasket so you don't sacrifice any more compression. Fel pro would be good. Nov 4, 8. Messages: 10, Likes Received: 1.
Please look into chevytech. I know that it's not finished or percent accurate, but, still, it's a darn good site, imho. Nov 4, 9. Messages: 8, Likes Received: Assuming that you want to use what you have: s will be better heads because of the bigger intake valves. They will not produce a huge power difference when compared to the heads though. As stated, use the Felpro steel head gaskets. Coat the head gaskets on both sides with aluminum spray paint or copper gasket sealer to help seal them to the block and heads.Only Chevelle-specific information is listed here to conserve space.
The casting number is probably the most significant feature on a cylinder head as it's the hardest to alter. The casting date is usually found near the casting number. It's important to remember the 'to' and 'from' dates listed may vary due to production lead time and stock inventories being depleted.
For example just because a particular head casting may be listed as being used from January to April doesn't imply that the engine assembly plants discarded all pre-January heads or on the 1st of May discard all heads they had in inventory to begin using the newer design. Casting clocks. Note the 11 dots plus the number 0 indicating the particular hour of a shift the heads were cast.
Cylinder heads are normally date coded in the form of a letter for the month see table belowtwo numbers for the day and a single number for the year. For example, C indicates a date of March 25, The top head is the 'lower horsepower' version hp and under used on applications with 1. These happen to be casting with Other 'pairs' of heads 1. There are over pages and images on this website. If you think there is something in error, please note the exact page by its address in your browser's window when reporting it.
Home Misc. Due to inventories, shipping schedules, etc. Combustion Chamber cc. Notes1. Casting symbol on exterior face of head is the infamous double-hump design. Has spark plug shield boss. It is debatable as to whether these plug shields were used on the Chevelle but the shields listed in Chevrolet parts books included the Chevelle application.
Used from January through May Used until January when replaced with June casting dates have been reported for this head. Has temperature sending unit boss. Production from May to May Identical to except it has the temperature sending boss. The late unit has the temperature sending unit boss but is not tapped.High-performance efforts have always begun by improving upon what the factory built, and the smallblock Chevy is the poster child for that effort.
This is a quick walk through the history and evolution of some of the better production heads, but the reality is that there are very few that are of any note. But in deference to the millions of castings that have made their way down the assembly line, we take a look at the few that are worthy of mention. This is the classic small-block production iron head from the mid s.
The earliest and small-blocks relied on an iron Power Pack head that featured cc chambers and tiny 1. The easiest way to reference any production head is with the last three digits of its casting number.
Small-Block Chevy Cylinder Head Identification
The most famous heads are the and heads that offer cc intake ports, cc chambers, and 2. For years, these were coveted castings in the performance community that were not superseded until the advent of the Chevy over-the-counter Turbo and Bow Tie iron pieces.
Even for many years after their introduction, the Bow Tie was considered exotic fare for street engines. These smaller chamber heads had better flowing ports than the later or castings. Around the mid s, several companies including Brownfield which was eventually purchased by AirFlow ResearchWorld Products, Brodix, Dart, and others began producing aftermarket iron and aluminum cylinder heads that were substantially better than the original small-block Chevy castings.
The Corvette heads turned out to be marginal, and by this time production heads were only considered for low-budget street engines. Then, inGM came up with the L31 Vortec engine package for light-duty trucks, using a new production cylinder head that quickly gained favor first among the roundy-pounders and then on the street. To look at the Vortec head, it appears to be just another iron production head. Its cosmetic changes include using centerbolt valve covers and a strange sawtooth i.
Otherwise, its cc intake port volume, cc chamber, and 1. But the chamber shape is much improved and the ports were born of performance heritage. Without a doubt, it is the best iron GEN I smallblock production cylinder head Chevrolet has ever produced.
Best Small Block Chevy Heads
Virtually overnight, a new subculture of budget small-block Chevy engines was created. We look at a few iron and aluminum production predecessors in more detail, but the majority of this chapter is devoted to the Vortec for obvious reasons.Gain extra benefits by becoming a Supporting Member Click here find out how! Send Private Topic View Profile. I have been told that the camel hump heads with 1.
This comes from a fairly knowledgable source. Since when are 's anything special? I always thought they are thin castings prone to cracks. Execution time: 0. All times are GMT Pacific. Current time is AM Top. Attach Photos to Posts. Contact Us. My Cookies. Frequently Asked Questions. Forum Rules. I have heads. I have been told they were good heads for the smog years, true or not true? I wonder how much more power I could get from a set of 2. Anyone have a link to some good informational reading about cylinder heads?
What is the chambers? My friend had some heads off a 95 and it has 64 cc chambers. The other numbers are the same.
I know after '75 Chevy cut costs, emissions, etc. On the other hand, my engine builder has a set that are still good i. I'm building a '76 sbc, bored. Am I dreaming with these heads or is my very reputable engine man being truthful with me? You guys rock and know your stuff, I humbly ask your opinions and am very thankful for them Please help me make an educated decision Thanks again!
There are two different types of 's - heavy and lightweight. The lightweight are crack prone, the heavy are not. If you want to only make hp, these heads will do it with some flat top pistons. The best factory heads are Vortec's that came on the last 's, but they take a specific intake and centerbolt valve covers.Some cynic once asked, "How can we miss you if you won't go away?
Every time we think we've come to the end of the Mouse motor saga, another good idea crops up, and we're back beating on this little small block Chevy engine on the dyno. While declaring a "winner" based on a simple nod to peak horsepower would be the quick and easy story, we planned to do more than just flog the obvious and call it a day. Instead, for our Best Small Block Chevy Heads, we have dyno curves, average power comparisons, and even dollar-per-average-horsepower evaluations.
We'll give you a thumbnail of each cylinder head and then show you the dyno numbers.Vortec Heads - Horsepower Improvements
With this broad of a selection, the only hassle might be choosing the best pair of heads. But the good news is that you will have plenty of information. Most of these small block Chevy heads offer a power increase of around 40 hp, and even the iron Vortec heads were worth 20 hp over stock.
The two best small block Chevy heads in terms of peak horsepower were worth more than 60 hp. But, as you'll see, there's much more to the story, so read on. The first thing we needed was a small block Chevy engine on which to evaluate power. Since this was a low-buck cylinder head test, we decided to use our budget small block Slayer engine from the May and June issues "Saturday Night Slayer" and "How to Run 11s".
The engine began life as a Goodwrench crate engine that we pumped up with a mild Summit Racing hydraulic flat-tappet camshaft and then abused with a hp nitrous hit.
The cam and nitrous were worth a whopping hp, and nothing hit the floor! Not satisfied, we yanked it apart, added a set of Federal-Mogul forged flat-top pistons and iron Vortec heads, and dropped this package into our Orange Peel '66 Chevelle. That combination ran As you'll see, the Vortec heads combination was worth barely hp, and the top five small block Chevy heads we tested would easily push the Chevelle into the mids without much difficulty.
We pulled the engine out of the Chevelle and stuck it on the dyno, still with the Summit flat-tappet cam and the Scoggin-Dickeymodified Vortec heads. Since most of these small block Chevy heads would benefit from additional lift, we also added a set of Harland Sharp 1.
While some of the heads offer good flow at 0. That would have required a roller cam, which we decided against because more than half of the field would have required a valvespring change. As it was, we were forced to use 1. We used the stock iron castings as the baseline cylinder head for comparison purposes.
This is the cc intake port head that comes on the Goodwrench crate engine and is representative of a typical 1. The flow numbers indicated the intake port wasn't able to reach even the cfm mark and that the exhaust was also unremarkable.
The baseline power numbers are also down due to reduced compression 8. This represents a difference of more than one point of compression or between 3 to 4 percent power.
We also weren't able to run a 1. We didn't have time to machine the heads, so we went with 1.