With 500-Inch Big-Blocks As The Norm, Cylinder Head Selection Has Never Been More Important
Hidden somewhere in this array of big-block cylinder heads is the perfect choice for your combination. Which one will you pick? Follow along as we give you the rundown on big-block Chrysler cylinder heads from mild to wild.
When it comes to bang for the buck, it's hard to beat a big-block Mopar. The wedge engine (named for its wedge-shaped combustion chamber) is a great combination of torque and horsepower and responds well to modifications. in production from the mid-'50s to the late-'70s, wedge engines were used in cars, trucks, and even motor homes, so finding one to build is usually as close as your nearest auto salvage yard. Another great thing about the wedge-it's an easy swap into any B- or C-body car that originally had a V-8, so it's common to see Satellites and Coronets with a 440 replacing their original 318. With kits available from several aftermarket companies, the big-block can also be swapped into slant six and A-body cars with minimal headache. While the big-block Mopar powerplant responds well to cam swaps, intake and exhaust modifications, and is capable of some pretty serious power with factory heads, the proper aftermarket heads could optimize your combination and shave a few pounds from the front of your car, but how do you choose the right head for your build? With so many factory and aftermarket cylinder head options, there is certainly an ideal head for your application. The trick is to pick the cylinder head that best fits your combination and meets your needs for horsepower, weight, and budget.
When Chrysler engineered their wedge heads in the '50s, they were lighter and more economical to manufacture than the first-generation Hemi cylinder heads. The early wedge heads had small valves and inefficient combustion chambers, but with the popularity of racing in the early '60s, the engineers at Chrysler pooled their resources to design the Max wedge cylinder head. Max wedge heads had larger ports and bigger valves than previous wedge heads. motors with these heads dominated drag racing and did well in other forms of motor sports until the re-introduction of the Hemi in 1964.
While the Max Wedge head is a great option, don't plan on using a set of these factory heads for your build. Factory Max wedge heads bring top dollar for restorations or Stock class drag racing applications and are scarce, so they're really not a viable option for the average street/strip engine.
With so many factory castings around and an endless supply of aftermarket options, which head is the best choice for your build? When we choose a cylinder head for one of our builds we first clearly define our goals. Is the car a street car, strip car, or will it serve dual purposes? Do we want the weight advantage of an aluminum head or the thermal advantage of a steel head? Are we going for all-out horsepower or will a factory head suffice? Most importantly, what is the budget for our build? Answering all these questions will narrow down the cylinder head choices for your project, but you may still find several heads that will satisfy your goals, then the choice is up to you.
The following cylinder head guide should help make the choice easier. Follow along as we describe and compare the popular factory heads, and let you know what is available from the aftermarket.
Factory Chrysler big-block heads, such as the 915 and 452 castings shown here, are plentiful and make respectable power even in stock form. These heads are a good choice for a stock engine or mild street engine and respond well to porting, but valve and port size limit their power potential.
Factory Cylinder Heads
When comparing factory Chrysler big-block cylinder heads we can break them down into three basic categories: Max wedge, open chamber, and closed combustion chamber. We won't consider the pre-'64, non-Max-Wedge heads because the rocker shaft and bracket system they utilized is not compatible with modern valvetrain components. Max Wedge heads are easily identifiable by the lack of a heat cross-over passage, large 1.88-inch exhaust valves, and very large ports. Casting numbers for the Max Wedge heads end in either 286, 209, or 518; keep an eye out at the swap meets in the unlikely event you'll run across a set of these desirable heads. While the Max Wedge heads do offer great power potential, they are expensive and hard to find, so unless you're building a Stock or Super Stock class racer, or restoring a factory race car, the cost of these heads is prohibitive for the average build.