440 Big-Block Build - Low Deck, Low Buck, High Power

Experience tells us that low-deck stroker motors of the type we're building make plenty of power, as even 906 headed versions can make upward of 550 horsepower and a bunch of torque. The common technique is to bore the 400 block to 4.380 inches, then either turn the main journals of the crank down, or line-bore the main journals of the block for the larger 440 crankshaft, giving a total displacement of just over 451 cubic inches. We chose to have Kevin at APE turn our crankshaft to the 400 main journal size, then clearance the weights to clear the block and balance the rotating assembly. APE also bored our block to accommodate our 440 Source forged pistons, and installed Pro-Gram Engineering's forged, cross-bolted main caps to strengthen the bottom end. With the makings of a stout short-block underway, we knew the only way to top this was with a set of good-flowing aftermarket cylinder heads. To put our big-block over the top, we chose a proven performance package from Indy Cylinder Head-their 440-1 kit.

We've used these and other Indy heads before on big-block Mopar engines, and we know they offer impressive flow numbers, especially when ported, resulting in big power. The raised port design of the 440-1 head requires valves with longer stems, external rocker oiling, and specially offset rocker arms, but luckily Indy offers a kit that gives you everything you need between the carburetor and the block, including the assembled heads, valve covers, intake manifold, rockers, oiling kit, and pushrods. Even better, Indy's price for this kit has changed very little over the past years, making it especially affordable in today's economy. In addition to the basic kit, we had our heads CNC ported by Indy, and we also had them install roller valvesprings from Comp Cams. For the best combustion chamber seal, we had these heads O-ringed and will install them with copper head gaskets from Summit Racing. The only drawback of the Indy heads is that their raised exhaust ports require the use of special headers. Fortunately TTI makes just the part number we needed, so we called and ordered a set of their mandrel-bent, coated, step headers for our application.

Knowing the heart of a performance engine is its camshaft, we picked a solid roller camshaft from Comp Cams. Despite what you may have heard, there's really no reason you can't run solid lifters in a street engine. Comp has less aggressive camshaft lobes that are designed specifically for street use and don't sacrifice power or throttle response like a hydraulic cam and lifter setup. We called Comp's cam help line, and after giving them the specifics of our application, we chose a solid roller cam with a total valve lift of .660 inch. Die hard racers will no doubt write in to say we need over .700-inch lift to maximize this combination, but remember this is a street engine and we don't want to wear out valvesprings any quicker than necessary. Even with this moderate roller cam, this engine should make plenty of power for a B-body that will be limited to street tires. To spin the cam, we ordered one of Comp's billet, adjustable, double roller timing sets with a Torrington style thrust bearing. Though not their least expensive timing set, this is an area where we just don't want to sacrifice because it's not significantly more expensive to buy the best parts.

So follow along as we build this stout, but moderately priced big-block for our '71 Road Runner. We'll show you all the parts and procedures we used to assemble this engine this month, and be sure to watch future issues as we'll upgrade the car's fuel and ignition system, install some safety equipment, then install the engine and run the car both on the chassis dyno and at the dragstrip. Log onto moparmusclemagazine.com as well for exclusive video and to tell us what you think of our combination.