Aftermarket big-block cylinder...
Aftermarket big-block cylinder heads offer numerous advantages over factory steel units. First and foremost, they'll shave some 40 pounds from the front of your vehicle. Big valves, efficient combustion chambers, and high flow numbers also make heads, such as the Mopar Performance Stage VI units shown here, a popular choice for performance builds.
Aftermarket Cylinder Heads
If your combination requires more flow than a factory head can support, or if you desire the weight savings of an aluminum cylinder head, an aftermarket head is your only choice. Edelbrock, Indy Cylinder Head, Brodix, and Mopar Performance offer numerous choices that can accommodate your need for power as well as your budget. Choosing the right aftermarket head depends on what you wish to achieve from your combination. Placing a large port, high-flow race head on your stock 383 is not a good choice, and the results will probably disappoint you. Conversely, a budget aftermarket head will certainly restrict that big cubic inch race motor you're building, netting similar, disappointing results.
In this section we'll outline aftermarket cylinder head selection by manufacturer and give you the lowdown on which head may be right for your combination.
Edelbrock
Performer RPM
Edelbrock Corporation has long been known for producing quality, affordable parts, so when they decided to produce their Performer RPM cylinder head for the big-block Chrysler we were certainly excited. These heads in stock form offer flow numbers comparable to ported factory heads, come completely assembled, are ready for cams up to .600-inch lift, and are priced reasonably. These heads come with large 1.81-inch exhaust and 2.14-inch intake valves right out of the box. Additional benefits are hardened valve seats and dry exhaust bolt holes meaning no more coolant leaks or messy sealer around the header bolts. These heads are completely interchangeable with factory units utilizing factory style rocker arms and valve gear that is oiled internally by the factory provision in the block. We saw a gain of more than 30 hp over fully prepped 452 castings by bolting a set of Performer RPMs to our 440 bracket motor, which was dyno tested in a previous issue. Comparing the cost of these heads against fully prepping a set of factory steel units really makes the choice a no-brainer.
 The Edelbrock Performer RPM... The Edelbrock Performer RPM cylinder head is a good economical choice for the big-block Chrysler engine. These heads come assembled and ready to bolt on and offer the performance of a fully ported and machined factory head. |  Right out of the box, the... Right out of the box, the Edelbrock Performer RPM heads offer port size and volume similar to the fully ported 452 casting on the right. Quality springs, hardened valve seats, and dry exhaust bolt holes make these heads a great choice for a street or mild race engine. |  Edelbrock heads, unlike some... Edelbrock heads, unlike some other aftermarket units, oil the valvetrain through the original passages in the block and don't require extra lines at the rear of the engine. The combustion chamber is a closed quench design offered in two sizes. Also notice the spark plug location is angled toward the exhaust valve, which promotes more efficient combustion. |
The Edelbrock Performer RPM...
The Edelbrock Performer RPM heads are available with either 84cc or 88cc combustion chambers. When compared to the open-chamber factory design on the right, the differences are apparent. The Edelbrock heads are a great choice for a street, strip, or dual-purpose vehicles, offering good performance at a reasonable cost.
Victor
Do Edelbrock's Performer RPM heads have you wishing they made a head with a little more potential? Rumor has it that Edelbrock will be releasing a Victor series head for the big-block Mopar that will offer flow and power potential similar to high-end race heads at a conservative cost. Watch for our upcoming engine challenge because at least one competitor has already decided to use the new Edelbrock Victors for his build!