If there's one thing that could be considered a cut above owning a Mopar musclecar, it's running that Mopar on the open road. Sure, there's the so-called "trailer queen" part of the hobby, but for most of us, the thrill in having something we can use. Hey, after all, it's your Mopar, and you can very well do what you want with it: shine it, show it, trailer it, race it, or drive it. That said, if you like your Mopars real-world ready and driveable, here's some food for thought.
Engine Endurance
1.Valvespring Variables
More often than not, when building a hot engine for that Mopar, a hotter cam and aftermarket valvesprings will be part of the package. While the easiest thing to do is squeeze the springs under the retainers, street (or race) survival depends on checking the basics. For example, what will be the lift at the valve with the cam and rocker ratio combined? Check for clearance between the top of the guide and the retainer at full lift. MP recommends a minimum clearance of .050 inch, but more is better, and don't forget to include the thickness of the guide seal.
Also, coil-bind clearance is essential, with a minimum of .050-.100, depending on whose specs you trust. Most springs are specified for coil-bind height; just subtract the valve lift from the installed height to decipher how much clearance is left. On the subject of installed height, a spring's load capability is directly proportional to its height, so knowing the load at the installed height is critical. Finally, for street use, don't get carried away with mega-big drag racing spring loads. Be realistic about your requirements-based on rpm and cam design-and select a spring that will perform the job without prematurely wearing out the valvetrain and pounding the seats. If in doubt about what's needed, consult an expert.
2. Oiling Options
A good street oiling system can range from radical and racy, such as the Milodon system pictured here, to OEM stock. The key is to match your requirements to the rpm range and use of the engine. The stock system works fine in a stock or mildly modified Mopar engine, big-block or small-block. A high-volume pump, coupled with minor mods such as a larger 1/2-inch NPT Hemi pickup in a big-block, along with some subtle passage massaging as outlined in the MP books, are all it takes to handle engine speeds through the mid-to-high sixes. Consider a windage tray mandatory in either engine family, and think seriously about adding a sump baffle in any open-sump pan to keep the pickup in the oil. Most importantly, stay clear of low-hanging, drag-style deep-sumps if any real street use is part of your plan; one pothole or speed bump will ruin your entire day.
3. Hassleless Headers
Headers add power, but low-clearance pavement draggers add headache, especially in the wilds of real street use. Rather than banging 'em in, get good ones that don't hang down. TTI makes a wide range of real full-length headers, such as the A-Body units above, which tuck much nicer than most. Other options include designs such as tri-Ys, shorties, or running the stock iron manifolds, though power won't match the benefits of full-length tubes.
4. Quality Counts
Adding reliability means shelling out for the good stuff where it counts. Here, we're preparing to install super-duty Arias forged racing pistons hung on bulletproof Eagle rods into a street engine. If that engine means anything to you over the long haul, stay away from the cheapo replacement goods and step up to real performance parts. Hypereutectics and forged slugs are hardier pistons than bargain-basement cast hand grenades and well worth the dough. Upgrading the fasteners, first in the rods, then the mains, and finally securing the heads, is the name of the game for long-term piece of mind. As power and rpm levels step up, so does your parts list, including aftermarket rods, forged cranks, blow-proof dampers, and so on; the list is endless. Those cheap, stock, old, or nasty parts may survive just fine, but be prepared for things to go wrong if you choose to roll the dice.