There's an old saying we remember that goes something like, "Horsepower sells cars, but torque wins races." Everyone brags about their humongous horsepower numbers, but when it comes to getting 3,000-lbs or more of steel moving in quick fashion then torque is the answer. Low-end grunt is what makes a street car fun. It's that push your eyeballs back into their sockets and wear a stupid grin on your face kind of deal. A racecar lives its life in the upper rpm, but a streetcar exists on the lower end where objects at rest want to stay put. To get a streetcar from zero to fast in a hurry you need torque and the quickest way to Torquesville is displacement.
One of the most common starting points for a big-block build is the venerable 454 Chevy block. You can still find them and the better ones can handle a huge amount of power. Best of all, they're ripe for the stroker treatment. Take a 454, add a 4.250-inch stroke crank along with some 6.385-inch rods and your displacement shoots up to 489 cubes. Now bore those cylinders out a touch, to say .060-inch over and you end up with the venerable 496. Those extra 42 cubes pay big dividends when it comes to churning out torque, and as a byproduct horsepower.
From an economics perspective, if you're replacing your rotating assembly, building a 496 barely costs more than a 454. Even if you were rebuilding a stock 454 it almost doesn't make sense these days to pass on going the stroker route. By the time you recondition your rods, grind your crank and possibly add new pistons, you're just a few bucks away from buying a brand new stroker kit.
The key to ending up with a reliable engine that makes good power is getting the machine work done correctly. We wanted it done right so we employed Andy Mitchell of Outlaw Racing Engines in Upland, California, to do the machine work and assembly. Andy had our '72 vintage 454 block cleaned, checked, and rough bored before finish honing the cylinders, with a torque plate, to .060-over. He also line-honed the block and cleaned up the decks. Could we have gotten away with less machine work? Maybe, but Andy likes to build them right the first time.
After getting organized, Andy started assembling the pistons and rods. Eagle is known for high-quality connecting rods and these forged 6.385-inch 5140 SIR I-beam units are no exception. They're bushed to work with full floating piston pins. The rods also utilize ARP fasteners and have alignment sleeves for easier assembly. They come packaged in weight-matched sets (+/- 2g) or they can be balanced by Eagle like ours were. The forged pistons are Mahle slugs and come coated right out of the box.
Attention to detail is critical when building any engine, especially one that is expected to churn out big power. Here Andy double checks the Clevite cam bearings we picked up from Summit Racing. He also organized the main caps and paired them up with the Clevite main bearings that were included in the Eagle stoker kit. Rather than reuse the old stock main bolts we spent a few extra bucks and went with stronger ARP main bolts (PN 135-5201, $53.95).